若有以下说明和语句：struct st{int n;char*ch;}struct st a[3]={5,"abc"7,"def",9",ghk"),*p=a;

若有以下说明和语句： struct st{int n;char*ch;} struct st a[3]={5,"abc"7,"def",9",ghk"),*p=a; 则值为6的表达式是______。

A．p++-＞n

B．p-＞n++

C．(*p).n++

D．#NAME？