定义类A和组合类B：class A
{
private: int x;
public: int y;
};...
单项选择题 定义类A和组合类B：class A
{
private: int x;
public: int y;
};
class B
{
public: A t;
int s;
}
使用组合类B定义对象：B obj; 下列语句中正确的是（ ）。
A．B *p = &obj; p->t.y = 5; p->s = 5;
B．B *p = &obj; p.t.x = 5; p.t.y = 5; p.s = 5;
C．obj.t.x = 5; obj.t.y = 5; obj.s = 5;
D．obj.x = 5; obj.y = 5; obj.s = 5;
