单项选择题

列程序的运行结果为
#include
template
class FF
TT al,a2,a3;
public:
FF(TT b1,TT b2,TT b3)a1=b1;a2=b2;a3=b3;
TT Sum( )return al+a2+a3;;
void main( )
FFx(int(1.1),2,3),y(int(4.2),5,6);
cout<
A.6.1 15.2
B.6 15
C.6 15.2
D.6.1 15