Can't execute 'Or' Command???

Hi, I have the following code that activates an error message when C is not combined with 4/10,4/101,4/146 and 5/112.
However, it calling an error on these options and I can't see how. I realise I should have put this as a Case argument rather than or which leads me to the question. Is there a limitation as to
how many or commands I can have. Maybe, this is affecting things?

Private Sub ComboBox10_Change()

If ComboBox7.Text = "C" And ComboBox10.Text = "4/100" Or ComboBox10.Text = "4/101" Or ComboBox10.Text = "4/146" Or ComboBox10.Text = "5/112" Then
'Do nothing
Else
MsgBox "P.C.D. NOT OFFERED", vbOKOnly + vbExclamation, "INCORRECT"
End If

End Sub