Q: On most side streets in the United States, the speed limit is 25 miles per hour unless otherwise posted. Traffic studies demonstrate that automobile drivers will go faster on side streets for which a speed limit of 25 miles per hour is posted than drivers will go on side streets for which no speed limit signs are posted. Psychologists believe that this is the case because simply seeing a speed limit sign makes drivers go faster because they feel less personally responsible for operating their vehicles at speeds appropriate to the conditions of the road.


Which of the following, if true, would most strengthen the psychologists'' explanation of the above mentioned studies?

A) The studies included both younger and older drivers, ranging from 16 to 89 years of age.

B) Drivers who feel personally responsible for operating their vehicles at speeds appropriate to the conditions of the road tend to drive faster when no pedestrians are present than they do when pedestrians are present.

C) In the vast majority of the cases in the traffic studies, those who drove slower did not feel personally responsible for operating their vehicles at speeds appropriate to the conditions of the road.

D) For the most part, drivers who feel personally responsible for operating their vehicles at speeds appropriate to the conditions of the road drive slower than those who do not feel personally responsible for operating their vehicles at speeds appropriate to the conditions of the road.

E) Generally, drivers will go faster on roads with higher posted speed limits than they will on roads with lower posted speed limits.