单项选择题

设有以下函数过程
Private Function Fun(a() as integer,b as string)as integer
……
End Function
若已有变量声明:
Dim x(5) as Integer,n as Integer ,ch as string
则下面正确的过程调用语句是( )。

A.x(0)=Fun(x,”ch”)
B.n=Fun(n,ch)
C.call Fun x,”ch”
D.n=Fun(x(5),ch)