When performing thorough examinations of patients with histories of he

• HIGHLIGHTS

Skip this part if you want only the PROCESS OF ELIMINATION, below, next bullet point.

"Check"? "Measure"? Which one? (Options A and B)

CHOOSE THE BETTER VOCABULARY WORD
-- sometimes GMAT uses different but synonymous words in order to distract.
-- sometimes, though, one word is better than the other.

Best case scenario: think of secondary meanings
In this case, one word is better.
-- to check does means to inspect.
But it also means to stop or hinder.
Correct: Quarantines usually check the spread of disease.

You could even think about the colloquial expression, "Check yourself," which means, "Stop yourself."

Although we understand the sentence with either measure or check, it would be better to use the word measure than to use the word check.
We don't want to imply that heart doctors sometimes stop blood from flowing.
Measure never means stop.
Avoid any chance of ambiguity.

Second best case scenario: compare the specificity and suitability of each word.

(1) Realize that the word check is less specific than measure. Do so by thinking of sentences.
-- Please check the soup on the stove. [Is it burning? Is it curdling? Is it doing something horrible?]
-- Please check the front door. [Is it locked? Is the noise that I hear someone knocking on the door? Is the door closed?]
-- Please check your temperature. [Pleasure measure your temperature.]
-- Please check with the concierge about our limousine service. [Go ask the concierge a question.]

Try to make sentences to get a more specific impression of meaning.
In Quant, we test small cases to find patterns for impossibly huge cases.
Try the same technique in SC.
Start thinking of sentences, which help us to get a better "feel" for the word.

ALTERNATIVELY
(2) realize that the word measure fits better with blood flow.
-- liquids flow at a rate.
-- to find out more about a rate, we measure it. Yes, we can "check" the rate. But the more precise and fitting word is measure.

Verb tense? Simple present? Simple future?

STATEMENTS THAT DESCRIBE GENERAL TRUTHS OR HABITS DO NOT USE "WILL" (Option C)
This sentence is a zero conditional: IF clause in simple present tense, THEN clause in simple present tense

The word "when" in the non-underlined portion locks us into a "zero conditional"
Only zero conditionals can use when in place of if.
When [if] water is heated, its volume expands.

(1) "Zero conditionals" express habits, general truths, scientific facts, and the like
If X happens, then Y happens.
If THIS thing happens, then THAT thing happens. (Not "will happen.")

X = THIS thing = WHEN or IF physicians perform thorough examinations of patients with histories of heart disease
Y = THAT thing = [then] sometimes those physicians measure blood flow

The author is not predicting. The word "when" tells us that the writer is describing a general truth or habit.
When we describe general truths or habitual actions, we can and often do use the word "when" rather than the word "if."

These three sentences are all zero conditionals. "When" is fine.
Correct: If it rains, sometimes the porch area gets wet.
Correct: When it rains, sometimes the porch area gets wet.
Correct: The porch area sometimes gets wet when it rains.

(2) Type 1 conditionals, by contrast, are often predictions or warnings.
Type 1: IF simple present, THEN simple future
Type 1 conditionals might be highly likely, but the outcome is not certain.
Some speculation exists.
We cannot use when in a Type 1 conditional.

This author is not speculating. The author is describing what happens (on occasion, but nonetheless always on occasion) in a certain context.
The verb "will" is not correct.

• PROCESS OF ELIMINATION

When performing thorough examinations of patients with histories of heart disease, physicians sometimes check the flow of blood.


• The word "check" can mean "stop."
• TENTATIVELY KEEP, but look for a better option


• the word "measure" is better than check. The word check could mean "stop."
KEEP (and eliminate A)


• The word "will" is incorrect. Compare to (B) in which no verb shift happens.
-- Does any good reason exist to shift verb tenses?
-- Is this writer talking about something that happens routinely or is a habit of the physicians?
If so, then simple present tense about what doctors DO (not "will do") is correct.

• The word "will" is incorrect because it suggests a prediction, not a statement about habit.
-- IF simple present, THEN simple future is used in Type 1 conditionals
-- we are dealing with a Zero Conditional
We are locked into a zero conditional because the word "when" is in the underlined part. "When" can be used rather than "if" only with Zero Conditionals
We need simple present (as in B), not simple future.
• This Type 1 (IF simple, THEN future), in other words, is not allowed.
Eliminate C


• modifier error: the flow of blood is not performing a thorough examination of anyone.
Eliminate D


• blood flow is not performing examinations
Eliminate E

The best answer is B

For more on conditionals, see my post here.

COMMENTS

I don't know whether GMAC would ask about the two words check and measure.
In this case (and in others on the GMAT), we have a chance to leave no room for ambiguity, so:
Leave no room for ambiguity. mykrasovski , I hope that answers your question.
GMAC really dislikes ambiguity.

But you all need not worry. Your answers are clear. Nice work. Kudos to all.