He didn not go by bike with me.That is ______there was something wrong with his bike.

A,why     B,how    C,because      D,Whether

系统中有R类资源m个，现由n个进程互斥使用。若每个进程对R资源的最大需求为w，那么当m、n、w取表4-1中的数值时，对于表4-1中的a～e共5种方案，（）可能会发生死锁。

A．a和b

B．b和c

C．c和d

D．c和e