窗体中有3个命令按钮,分别命名为Command1、Command2和Command3。当单击Command1按钮时,Command2按钮变为可用,Command3按钮变为不可见。下列Command1的单击事件过程中,正确的是()
A.private sub Command1_Click() Command2 B.private sub Command1_Click() Command2 C.private sub Command1_Click() Command2 D.private sub Command1_Click() Command2