It was not easy for him to buy good shoes because he had such a big _____ of feet.

A．couple

B．size

C．number

D．pair

为了避免在嵌套的条件语句if-else中产生二义性，C++语言中规定的if-else匹配原则是( )。

A．else字句与所排位置相同的if配对

B．else子句与其之前最近的if配对

C．else子句与其之后最近的if配对

D．else子句与同一行上的if配对