I need my macro to reset the data validation for D6 each time it is run as
the range of rows will increase as new info is added. How can I do this?

Range("D6").Select
With Selection.Validation
.Delete
.Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
xlBetween, Formula1:="=$A$1:$A$547"
.IgnoreBlank = True
.InCellDropdown = True
.InputTitle = ""
.ErrorTitle = ""
.InputMessage = ""
.ErrorMessage = ""
.ShowInput = True
.ShowError = True
End With