A- outside scope of argument , no discussion on "alternate transport"

B -not giving drops to patient does not support the argument.

C - correct - if they rated their abilities conservatively, then the actual effect of eye drops will be less prolonged, which supports the argument

D - there is no discussion of time to regain abilities is made in argument that do not play role in driving

E -opposes the argument b giving preference to general population.

IMO C.

Conclusion: many eye patients who had eye drops prior to the examination are unlikely to follow the physician's precautions.

Premise: a recent hospital study featuring in-patients, questioned the usefulness of abstaining for 24 hours when the effect of eye drops wanes within 4 hours.

Assumption: The ideas of in- patients are the same as ideas of general patients.

We need to strengthen this assumption.

A. People, when they know that they will receive eye drops, make alternate transport arrangements to take them home. [ This will weaken the statement coz it tells that patients follow physicians precautions and hence make alternate arrangement. Eliminated!]

B. Some patients request the doctors not to give them eye drops that blur vision if they will have to drive to get home afterward. [This by no way addresses a general population. 'Some' can mean one person also. what applies to one person need not be true of general patient population. Eliminated!]

C. The subjects in the hospital study generally rated their abilities more conservatively than they would if they were outside the framework of a scientific experiment. [Bingo! Correctly strengthens the assumption and provides a reason why the survey that takes the opinion of in patients is true for general patients.]

D. The subjects in the hospital study were also questioned about the time necessary to regain abilities that do not play an important role in driving safely. [What were the question asked in the survey is not important. Why in patients opinion translates to general patient population is important. Eliminated!]

E. Awareness of the effect of eye drops is higher among the general population than it was among the subjects in the hospital study.[This is again a weakner.If the awareness is high, they would better accord to what the physicians tell rather than going against their prescriptions. Eliminated!]

Hope this helps!