单项选择题
窗体上有一个名称为Command1的命令按钮，其中部分代码如下：
Private Sub Command1_Click( )
Dim a(10) As Integer
Dim n As Integer
……
Call calc(a,n)
……
End Sub
calc过程的的首行应该是（）。
A．Sub calc（x() As Integer,n As Integer）
B．Public Sub calc(x() As Integer)
C．Private Sub calc(a(n) As Integer,n As Integer)
D．Public Sub calc(a As Integer, n As Integer)