"I'm pretty sure what I said was right"... Just a tip; remember the principle of PRIMACY when teaching. Much better off to just say "I don't know" "I'm not sure" "We need to research that/look it up" "I'll research that" Etc. If you aren't sure it's generally best not to offer anything up. Students are like sponges (Hopefully)They will remember everything you say and do. It's much harder to undo something already in the students head and can lead to other issues as well. Also remember Class D can change to another category... Keep asking questions, nobody knows it all. (And fear those that do...)