VBA - Add Font Bold

Private Sub Worksheet_Change(ByVal Target As Range)
With Target
If .Count > 1 Then Exit Sub
If .Column = 3 Then
If .Value = "m/c interest" Then
.Offset(, 2).Value = Range("L2").Value
ElseIf .Value = "interest" Then
.Offset(, 2).Value = Range("L3").Value
.Offset(, -1).Value = DateSerial(Year(Now), Month(Now) + 1, 0)
ElseIf .Value = "web internet" Then
.Offset(, 2).Value = Range("L4").Value
ElseIf .Value = "cell phone" Then
.Offset(, 2).Value = Range("N2").Value
End If
ElseIf .Column = 5 Then
.Offset(, -3).Value = Date
ActiveSheet.Unprotect "r"
Target.Locked = True
ActiveSheet.Protect "r"
End If
End With
End Sub

this part of code font bold

.Offset(, -1).Value = DateSerial(Year(Now), Month(Now) + 1, 0)

Thanks