With Sheet1 containing in Cells A1:A11

a1
a2
a3
a4
b1
b2
b3
b4
c1
c2
c3

Why is this code Not deleting
all and only the ?3's and ?4's

Right Now it is deleting ALL/everything !!
Hair-pulling here ...

Sub foo()
Set rng = ActiveSheet.Range(Cells(1, 1), Cells(Cells(Rows.Count,
1).End(xlUp).Row, 1))
lrow = rng.Rows.Count
For i = lrow To 1 Step -1
t = Right(Cells(i, 1).Value, 1)
If t < "1" Or t < "2" Then
Cells(i, 1).EntireRow.Delete
End If
Next
End Sub