【单选题】

已知x代表某个百分制成绩，下列程序段用于显示对应的五级制成绩，正确的是（）

A)If x > = 60 Then
Print "及格"
ElseIf x > = 70 Then
Print "中"
ElseIf x > = 80 Then
Print "良"
ElseIf x > = 90 Then
Print "优"
Else
Print "不及格"
End If
B)If x < 90 Then
Print "良"
ElseIf x < 80 Then
Print "中"
ElseIf x < 70 Then
Print "及格"
ElseIf x < 60 Then
Print "不及格"
Else
Print "优"
End If
C)If x > = 90 Then
Print "优"
ElseIf x > = 80 Then
Print "良"
ElseIf x > = 70 Then
Print "中"
ElseIf x > = 60 Then
Print "及格"
Else
Print "不及格"
End If
D)Select Case x
Case x > = 90
Print "优"
Case x > = 80
Print "良"
Case x > = 70
Print "中"
Case x > = 60
Print "及格"
Case Else
Print "不及格"
End Select