问题详情

Themainideaofthispassageisthat______.
A．trafficaccidentsaremainlycausedbymotorists
B．thousandsofpeopleovertheworldarekilledeachyear
C．thelawsofsomecountriesaboutdrivingaretoolax
D．onlystrictertrafficlawscanpreventaccidents
请帮忙给出正确答案和分析，谢谢！