Listening to music while you drive can improve your reaction time and ability to avoid haz

ards, according to Australian psychologists. But turning your car stereo up to full volume could probably make you end up in an accident.

The performance of complex tasks can be affected if people are subjected to loud noise. The experience of pulling up at traffic lights alongside cars shaking with heavy bass (低音) prompted some psychologists in the University of Sydney to investigate whether loud music interferes with driving.

The psychologists recruited 60 men and women aged between 20 and 28 as subjects and tested them on simulated (模拟的) driving tasks under three noise conditions: silence, rock music played at a gentle 55 decibels, and the same music roaring out at 85 decibels. For 10 minutes the subjects sat in front of a monitor operating a steering wheel and foot pedals representing the brake and accelerator (加速器). They had to track a moving disk on screen, respond to traffic signals changing color, and brake in response to arrows that appeared without warning.

On the tracking task, there was no difference in performance under the three noise conditions. But under both the loud and quiet music conditions, the volunteers "braked" at a red light about 50 milliseconds sooner than they did when there was no rock music at all. That could mean a reduction in braking distance of a couple of meters potentially, the difference between life and death for a pedestrian (行人). When it came to the arrows that appeared across the visual field, the psychologists found that when the music was quiet, people responded faster to objects in their central field of vision by about 50 milliseconds. For those listening at 85 decibels, response times dropped by a further 50 milliseconds -- a whole tenth of a second faster than those "driving" with no music.

"But there is a trade-off (交换)", the psychologists told the European Congress of Psychology, "They lose the ability to scan the environment effectively." In responding to objects intruding on their peripheral(周围的)vision, people subjected to 85-decibel rock music were around 100 milliseconds slower than both the other groups. Since .some hazards -- such as children running into the road -- emerge from the periphery, drivers listening to loud music must be less safe as a result.

Which of the following is the best way to make a driving safer？

A．Loud music.

B．Quiet music.

C．Silence.

D．Full volume stereo music.