question 1

After the national speed limit of 55 miles per hour was imposed in 1974, the number of deaths per mile driven on a highway fell abruptly as a result. Since then, however, the average speed of vehicles on highways has risen, but the number of deaths per mile driven on a highway has continued to fall.
Which of the following conclusions can be properly drawn from the statements above?


A The speed limit alone is probably not responsible for the continued reduction in highway deaths in the years after 1974.
B People have been driving less since 1974.
C Driver-education courses have been more effective since 1974 in teaching drivers to drive safely.
D In recent years highway patrols have been less effective in catching drivers who speed.
E The change in the speed limit cannot be responsible for the abrupt decline in highway deaths in 1974.