I made an account here pretty much just to ask this question.
I searched the forums before I considered posting, I found nothing that addresses this issue. I'm sure it's a simple fix, and I really hope it DOESN'T involve scripting.

My question is thus:

How can I delete or remove a topic from the topic menu AFTER it's been used?

Let's say I have a topic that is automatically added when a character greets the player for the first time. The player clicks on that topic, dialogue is given, and the npc presents a choice. After picking one of these choices (The other choice is a goodbye), another new topic is added to the menu. How can I remove the topic that presented the choice from dialogue?

If I am in the wrong in someway, forgive me. I've searched all over and I can't find an answer to this simple question.