Matt Groening and The Simpsons

I'm glad this wasn't my question, because I would have answered "Homer Simpson" – and what would the question asker have done with that?

I was under the impression that Matt Groening was the creator of The Simpsons, and I take that to mean he created all the characters – at least all the principal ones. The one who was a nuclear power plant operator was Homer; how this question is supposed to lead me to Bart, I do not know.