Question

the high collision rate of beginning drivers is due mostly to a inadequate traffic enforcement. b lack of experience. c use of older cars. d low minimum licensing age.

Explanation:

Beginning drivers are new to driving, so their high collision rate is mainly because they haven't had enough time on the road to gain skills and judgment, which is lack of experience. Inadequate traffic enforcement (A) would affect all drivers, not just beginners. Use of older cars (C) isn't a primary reason for beginner collisions as it's not specific to them. Low minimum licensing age (D) doesn't directly cause collisions; a young driver with experience would be better, so lack of experience is key.

Answer:

B. lack of experience.