Increases in the level of high-density lipoprotein (HDL) in the human

Question

Increases in the level of high-density lipoprotein (HDL) in the human bloodstream lower bloodstream cholesterol levels by increasing the body’s capacity to rid itself of excess cholesterol. Levels of HDL in the bloodstream of some individuals are significantly increased by a program of regular exercise and weight reduction.

Which of the following can be correctly inferred from the statements above?

(A) Individuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream.

(B) Individuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in life.

(C) Exercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans.

(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.

(E) Only regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.

BrentGMATPrepNow · Accepted Answer

When answering inference questions on the GMAT, are looking for the answer choice that  MUST  follow from the premises. So, as we examine the answer choices, we must  aggressively eliminate  any answer choice that does not necessarily follow from the premises.

(A) Individuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream. 
The passage says that SOME people on a weight reduction program may see increased levels of HDL. This does not mean that underweight people will NEVER have high levels of cholesterol. 
Eliminate answer choice A 
 
 (B) Individuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in life. 
There is nothing in the passage that guarantees this to be true. All we are told is that SOME people who exercise may see increased levels of HDL. We are not given any information about people who do NOT exercise. 
Eliminate answer choice B

(C) Exercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans. 
The MOST EFFECTIVE? This language is too strong. All we are told is that SOME people who exercise and are on a weight reduction plan may see increased levels of HDL. That's it. There's nothing here that says this is the BEST way to reduce cholesterol. 
Eliminate answer choice C

(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals. 
Notice how the language in this house for choice matches the language in the passage. In the passage we are told that SOME people see lowered cholesterol levels. This answer Choice also uses the limiting word SOME. 
Keep answer choice D

(E) Only regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight. 
ONLY regular exercise?? 
This language is too strong also. The passage tells us that SOME people who regular exercise will see decreased levels of cholesterol. There is nothing in the passage that suggests that regular exercise is the ONLY way to decrease levels of cholesterol. 
Eliminate answer choice E.

By the process of elimination the correct answer is D.

Cheers,
Brent

DAVEexamPAL · Answer

The answer is D.  
We can solve this  Logically , by spelling out what we can infer logically from the passage: 
if high HDL leads to lower cholesterol, and exercise and weight reduction lead to high HDL,  it follows that exercise and weight reduction > lower cholesterol. This is exactly what (D) tells us.

As always, we can also take the  Alternative  approach and  use the answers:

(A) Individuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream. logical fallacy - just because x (being overweight) leads to y (risk of high cholesterol) doesn't mean that not x leads to not y!

(B) Individuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in life.  logical fallacy again - just because x (exercising regularly) leads to y low cholesterol) doesn't mean that not x necessarily leads to not y!

(C) Exercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans.  all we know is that they are effective, nowhere is it stated that they are THE MOST

(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.  yup - logical conclusion of the information: if x leads to y and y leads to Z, it follows that x==> z

(E) Only regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.  Nope - all we know is that it helps. nowhere does it say that ONLY it is enough

Prasannathawait · Answer

D is the right answer.
Other answer choices are too strong and might not necessarily be true.

Raxit85 · Answer

Option D is direct inference of the paragraph. Option C could be or couldn't be true, whereas other options are out of context of the paragraph. Hence, D is the correct answer.

merajul · Answer

Increases in the level of high-density lipoprotein (HDL) in the human bloodstream lower bloodstream cholesterol levels by increasing the body’s capacity to rid itself of excess cholesterol. Levels of HDL in the bloodstream of some individuals are significantly increased by a program of regular exercise and weight reduction.

Which of the following can be correctly inferred from the statements above?

(A) Individuals who are   underweight   do not run any risk of developing high levels of cholesterol in the bloodstream.

(B) Individuals who   do not exercise regularly have a high risk   of developing high levels of cholesterol in the bloodstream late in life.

(C) Exercise and weight reduction are   the most effective methods   of lowering bloodstream cholesterol levels in humans.

(D)  A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.

(E)   Only regular exercise   is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.

BLTN · Answer

Increases in the level of high-density lipoprotein (HDL) in the human bloodstream lower bloodstream cholesterol levels by increasing the body’s capacity to rid itself of excess cholesterol. Levels of HDL in the bloodstream of some individuals are significantly increased by a program of regular exercise and weight reduction.

X  (Increase of HDL) --- >  Y  (lower cholesterol levels )
 Z  (Program of regular exercise and weight reduction) - >  X  (Increases of HDL)

Hence, Z -- > X -- > Y =  Z --- > Y

(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.
 Z -- > Y

egmat · Answer

The correct answer:  D.

Passage Analysis:

1. Increase in HDL in the bloodstream -> Increase in the body's capacity to remove excess cholesterol -> Decrease in cholesterol levels in the bloodstream
2. A program of regular exercise and weight reduction -> Increase in bloodstream HDL in  some  individuals

Prethinking: 
By combining the 2 statements, we can infer that -

For some individuals , a program of regular exercise and weight reduction will lead to a lowering of cholesterol levels in the bloodstream.

Answer Choice Analysis:

(A) Individuals who are underweight do not run any risk of developing high levels of cholesterol in the bloodstream.

No information to infer about underweights. Just because a program of weight reduction can lower cholesterol in some people, it does not imply that underweight people have 0 risk of developing high cholesterol.

(B) Individuals who do not exercise regularly have a high risk of developing high levels of cholesterol in the bloodstream late in life.

Just because a program that involves regular exercise can lower cholesterol in some people, it does not mean that those who do not exercise regularly have a high risk of high cholesterol. While exercise may help with lowering cholesterol, a lack of exercise does not necessarily mean high risk of high cholesterol.

(C) Exercise and weight reduction are the most effective methods of lowering bloodstream cholesterol levels in humans.

"MOST EFFECTIVE" is the issue. All we know is that exercise and weight reduction help lower cholesterol in some individuals. It does not mean that they are the most effective. There may be 100 other methods which are more effective.
 
(D) A program of regular exercise and weight reduction lowers cholesterol levels in the bloodstream of some individuals.

Correct. This is in line with our prethinking.

(E) Only regular exercise is necessary to decrease cholesterol levels in the bloodstream of individuals of average weight.

All we know is that in some cases, regular exercise helps. Is it the only method that is necessary? We have no idea.

Option D is correct.

av722 · Answer

Because this is an inference question, we must chose the choice that  must be  true, not could potentially be true.

A: This goes too far. It never mentions underweight people.
B: The passage mentions regular exercise + weight reduction can signficantly increase HDL levels. It never says anything about the reverse scenario. 
C: This choice goes too far by saying it's the 'most effective' method.
 D: This choice restates the last sentence. Correct.  
E: E goes too far by mentioning 'only exercise...'

Nsp10 · Answer

a very bood basic Inference Q, 
HDL increases then cholesterol decreases,
regular exercise will increase HDL so cholesterol will decrease
stratight D

Increases in the level of high-density lipoprotein (HDL) in the human

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Increases in the level of high-density lipoprotein (HDL) in the human

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