Funny Students

Right now, my students have to come up with a research topic, then put it in the form of a question for approval. The point is to have them then do research, then answer the question in two sentences as a starting point for their paper. I had the following email exchange (I've edited it to make it easier to read):

Him: I'd like to write about the role of the Black Hand in the outbreak of World War I.
Me: That sounds like a good idea. Phrase it in the form of a question, and I'll approve it. [followed by an explanation of why]
Him: Okay. My research question is that I want to know what the role of the Black Hand was in causing World War I.
Me: This is going to drive you nuts, but I want you to put it in the form of a question--with a question mark.
Him: [finally makes it a question]
Me: [I finally approve it]

I asked myself where I went wrong, and I can't figure it out. I guess he just didn't understand what "question" means.