Type mismatch error trying to removing item from listbox.

Hi everyone. I am working on an activity to help students match instruments to sounds. I have them in a list called InstrumentList, and the student answer is in StudentAnswerLBL.caption.

I thought this would work,

Main.InstrumentList.RemoveItem Main.StudentAnswerLBL.Caption

but I get a type mismatch error. Am I missing something? Thanks!