Alternate Cause - A weakener or not

Forgot to share official questions for X led to Y:

In the last decade there has been a significant decrease in coffee consumption. During this same time, there
has been increasing publicity about the adverse long-term effects on health of the caffeine in coffee.
Therefore, the decrease in coffee consumption must have been caused by consumers’ awareness of the
harmful effects of caffeine.
Which of the following, if true, most seriously calls into question the explanation above?
(A) On average, people consume 30 percent less coffee today than they did 10 years ago.
(B) Heavy coffee drinkers may have mild withdrawal symptoms, such as headaches, for a day or so after
significantly decreasing their coffee consumption.
(C) Sales of specialty types of coffee have held steady as sales of regular brands have declined.
(D) The consumption of fruit juices and caffeine-free herbal teas has increased over the past decade.
(E) Coffee prices increased steadily in the past decade because of unusually severe frosts in coffee-growing
nations.

Option E is the correct choice.


Which of the following most logically completes the argument given below?
People in isolated rain-forest communities tend to live on a largely vegetarian diet, and they eat little salt. Few of
them suffer from high blood pressure, and their blood pressure does not tend to increase with age, as is
common in industrialized countries. Such people often do develop high blood pressure when they move to cities
and adopt high-salt diets. Though suggestive, these facts do not establish salt as the culprit in high blood
pressure, however, because .
(A) genetic factors could account for the lack of increase of blood pressure with age among such people
(B) people eating high-salt diets and living from birth in cities in industrialized societies generally have a
tendency to have high blood pressure
(C) it is possible to have a low-salt diet while living in a city in an industrialized country
(D) there are changes in other aspects of diet when such people move to the city
(E) salt is a necessity for human life, and death can occur when the body loses too much salt

Option D is the correct choice.


Though sucking zinc lozenges has been promoted as treatment for the common cold, research has revealed no consistent effect. Recently, however, a zinc gel applied nasally has been shown to greatly reduce the duration of colds. Since the gel contains zinc in the same form and concentration as the lozenges, the greater the effectiveness of the gel must be due to the fact that cold virus tend to concentrate in the nose, not the mouth. Which of the following, if true, most seriously weakens the argument?
A. Experimental subjects who used the zinc gel not only had colds of shorter duration but also had less severe symptoms than did those who used a gel that did not contain zinc.
B. The mechanism by which zinc effects the viruses that caused the common cold has not been conclusively established.
C. To make them palatable, zinc lozenges generally contains other ingredients, such as citric acid,, that can interfere with the chemical activity of zinc.
D. No Zinc based remedy can have any effect unless it is taken or applied within 48 hrs of the onset of cold symptoms.
E. Drug company researchers experimenting with nasal spray based on zinc have found that it has much the same effect on colds as the gel does.

Option C is the correct choice.

In Morigia the average age of cars that are still in use has historically been seven years, but now it is nearly nine years. Car manufacturers claim that the current poor economy has forced people to put off buying new cars, and thus when the economy improves, the average age of cars will return to former levels. Which of the following, if true, most seriously calls into question the car manufacturers' prediction?
A. Fewer cars per year are now being manufactured in Morigia than were being manufactured there five years ago.
B. When the threat of job loss is particularly strong, people are reluctant to commit themselves to expensive purchases.
C. The older a car is, the greater the amount of upkeep it requires.
D. The air-pollution control devices now being used in cars manufactured in Morigia cost less than those that were used seven years ago.
E. Most people in Morigia now believe that replacing an old car with a new one has very undesirable ecological consequences.

Option E is the correct choice.

Thanks,
Chiranjeev