Hmmm, this is a "type what you hear" question, so "Tha ceann mòr agam." is correct in that this is what was said, however, I thought that the correct way to say "I have a big head." is "Tha ceann mòr orm." No?
Yes, that's my point. In other discussions it was mentioned to not use "agam" in this instance, so I'm not sure it's a good idea for the course to have this question - it may reinforce an incorrect usage and confuse people (like me).