单项选择题

把窗体的Key Preview属性设置为True,然后编写如下过程:
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
Print Chr(KeyCode)
End Sub
Private Sub Form_KeyUp(KeyVode As Integer, ShiftAs Integer)
Print Chr(KeyCode+2)
End Sub
程序运行后,如果按“A”键,则输出结果______。

A.A
B.A
C.A
D.A
A B C D