Struct student { int age;char num[8];}; Sturct student stu[3]={{20,"200401"},{21,"200402"},{10\9,"20043"}}; Struct student *p=stu; 以下选项中引用结构体变量成员的表达式错误的是( ) A)(p++)->num B)p->num C)(*p).num D)stu[3].age求每一项解释