有如下类声明： class XA { int x; public: XA(int n) {x=n;} }; class XB: public XA{ int y; public: XB(int a,int b); };在构造函数XB的下列定义中，正确的是______。

A．XB:: XB(int a, int :x(,y( { }

B．XB::XB(int a, int :XA(,y({}

C．XB::XB(int a,int :x(,XB(i}

D．XB::XB(int a,int :XA(,XB({}

I don't________of your sending your daughter to Britain to study, because she is too young.[ ]

A. agree  

B. approve

C. support  

D. assess