单项选择题

设有如下程序: Private Sub search(a()As Variant,ByVal key As Variant,index%) Dim I% For I = Lbound(a)To Ubound(a) If key=a(I)Then index=I Exit Sub End If Next I index=-1 End Sub Private Sub Form_Load() Show Dim b()As Variant Dim n As Integer b=Array(21,64,92,15,72,38,45,72) Call search(b, 45, n) Print n End Sub 程序运行后,输出的结果是

A.2
B.6
C.10
D.12