I am not sure what the point is about the code lines that you have added like
Range("R19").Select
Range("R19").ClearComments
???
Reason for adding the line Range("R19").ClearComments:
Actually, I've added a line in the Macro which add a comment box in the Cell R19 automatically, after Selecting "Single-Parent Family" in the cell RJ. So, it needs to be cleared on changing selection.

Reason for adding the line Range("R19").Select
I want that when a value is selected in the cell J19, the cursor automatically moves to the cell R19 to get the attention of the user, so that the user can easily enter the remarks, or take a look, at least. (Sorry That I was forget to mention it in my previous reply)

Here is the added code...

Code:
ElseIf RngTgt.Value = "Single-Parent Family" Then
         Let Application.EnableEvents = False
         Let Range("R19").Value = "(Select Reason for Single-Parent)"
         Let Application.EnableEvents = True
         Let Range("R19").Font.Color = 10855845
         Let RngTgt.Font.Color = 6751362
            With Range("R19").Validation
              .Delete
              .Add Type:=xlValidateList, AlertStyle:=xlValidAlertStop, Operator:= _
              xlBetween, Formula1:="Expired {One is No More},Divorced {Separated Legally},Break-Up {Attachment Hampered},Abandonment {Fully Separated},Enter Reason Manually"
              .IgnoreBlank = True
              .InCellDropdown = True
              .InputTitle = ""
              .ErrorTitle = "Error!"
              .InputMessage = ""
              .ErrorMessage = "To enter the reason manually, please select the option 'Enter Reason Manually'"
              .ShowInput = True
              .ShowError = True
            End With
             Range("R19").Select
             Range("R19").AddComment
             Range("R19").Comment.Visible = False
             Range("R19").Comment.Text Text:="Reason for Single-Parent"