听力原文： As the car industry develops, traffic accidents have become as familiar as the c

听力原文： As the car industry develops, traffic accidents have become as familiar as the common cold. Yet their cause and control remains a serious problem that is difficult to solve. Experts have long recognized that this discouraging problem has notable causes. At the very least, it is a problem that involves 3 factors: the driver, the vehicle and the road way. If all drivers exercised good judgment at all times, there would be few accident. But this is rather like saying that if all people were honest, there would be no crime. Improved design has helped to make highways much safer. But the tide of accidents continues to rise because of human failure and the enormous increase in the number of automobiles on the read. Attention is now turning increasingly to the third factor of the accident, the car itself. Since people assume that accidents are bound to occur, they want to know how cars can be built better to protect the drivers.

What does the speaker think of the causes of automobile accidents？

A．The causes are obvious.

B．The causes are very complicated.

C．The causes are familiar.

D．The causes are not well understood.

请帮忙给出正确答案和分析，谢谢！