若有以下说明:
Int a[12]={1,2,3,4,5,6,7,8,9,

若有以下说明:
Int a[12]={1,2,3,4,5,6,7,8,9,10,11,12};
Char c='a',d,g;
则值为4的表达式是______。

A.a[g-c]

B.a[4]

C.a['d'-'c']

D.a['d'-c]

正确答案是D