This program is for a homework and I have most part of it till the part where I have to add $2 or $1 if the hours per months passed the limit. Can someone help me with this code?

This is the code I have till now:

Private Sub Calculate_Click()

'Variables
Dim MC As Double
Dim lblMC As Currency

'Input Validation
If txtHC.Value = "" Then
txtHC = InputBox("Please enter a number of hours")
ElseIf txtHC > 744 Then
txtHC = InputBox("Hours of Access cannot be higher than 744 hours")
End If

'Process
If radA.Value = True Then
MC = 9.95
ElseIf radB.Value = True Then
MC = 14.95
ElseIf radC.Value = True Then
MC = 19.95
End If
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