单选题 California was forced to adopt this plan because ______.

A、 a recent oil crisis necessitated it
B、 too many drivers were filling their tanks with more than twenty gallons and spilling it
C、 people were not getting enough exercise and need to walk, bike, or skate
D、 too many motorists had odd-numbered plates

【正确答案】 A

【答案解析】该题为句义理解题。由文章开头As a result of the recent oil crisis．．．可以确定A为正确答案。