Sub Test()
Dim x, ws As Worksheet, sh As Worksheet, s As String, m As Long
Application.ScreenUpdating = False
Set ws = Worksheets(1)
Set sh = Worksheets(2)
sh.Range("B7:B" & Rows.Count).ClearContents
s = sh.Range("AI3").Value
If s = "" Then MsgBox "Select Grade First", vbExclamation: Exit Sub
x = Application.Match(s, ws.Rows(1), 0)
If IsError(x) Then MsgBox "No Data For This Grade", vbExclamation: Exit Sub
m = ws.Cells(Rows.Count, x).End(xlUp).Row
If m < 4 Then MsgBox "No Data", vbExclamation: Exit Sub
sh.Range("B7").Resize(m - 3).Value = ws.Cells(4, x).Resize(m - 3).Value
Application.ScreenUpdating = True
End Sub