某人编写如下函数来判断a是否为素数，若是，则函数返回True；否则返回False。
Function prime(a As Integer)As Boolean
Dim k As Integer,isprime As Boolean
If a＜2 Then
isprime=False
Else
isprime=True
k=2
Do While k＜a/2 And isprime
If a Modk=0 Then
isprime=False
Else
k=k+1
End If
Loop
End If
prime=isprime
End Function
在测试时发现有1个非素数也被判断为素数，这个错判的数是( )。

A．Type SystemInfo
DiskDrives As String*10
Memory As Long
End Type
B．Type SystemInfo
DiskDrives As String*10
Memory As Long
End SystemInfo
C．Type SystemInfo
DiskDrives String*10
Memory Long
End Type SystemInfo
D．Typedef SystemInfo
DiskDnves String*10
MemoryLong
End Type

A．2
B．3
C．4
D．5