学进去

有如下程序段
Dim n As Integer, i As Integer, left As Integer, right As Integer, m As Integer
Dim a(1 To 10) As String, t As String, key As String
n = 6
a(1) = "35": a(2) = "20": a(3) = "18": a(4) = "8": a(5) = "274": a(6) = "47"
For i = 1 To n - 1
For j = n To i + 1 Step -1
If a(i) < a(j) Then
t = a(i): a(i) = a(j): a(j) = t
End If
Next j
Next i
key = Text1.Text
left = 1: right = n
Do While left <= right
m = (left + right) \ 2
If a(m) = key Then Exit Do
If a(m) < key Then right = m - 1 Else left = m + 1
Loop
若在文本框 Text1 中输入“212”，则程序运行结束后，m 的值为(   )

A．1

B．2

C．4

D．5