负债程度越高，综合资金成本越低，企业价值越大，当负债比率达到100%时，企业价值将达到最大，这是( )的观点。

A．净营业收益理论

B．净收益理论

C．MM理论

D．平衡理论

请根据下面短文回答下列题：
Safety Rules for Bike-Riding.
1. Never ride out into a street without stopping first.
2. Watch for stop signs.
3. Look behind before turning or changing lanes (车道) .
4. Always ride on the right.
5. Never follow another rider without applying the rules.
Remember, your bicycle is a small compared with cars and trucks. It is not easily seen on crowded streets and will seldom attract attention on its own. At all times, do everything you can to make sure you are noticed.

Whom are these safety- rules for
[A] People who drive.
[B] People who ride bikes.
[C] People who walk.