单选题：下列对结构体类型变量定义不正确的是

下列对结构体类型变量定义不正确的是





A. struct teacher{int num; int age;}teach1;


B.struct {int num; int age;}teach1,teach2;


C.struct {int num; int age;}teacher; struct teacher teach1;


D.struct teacher {int num; int age;}; struct teacher teach1;




answer：C