I'd say A & B both. He certainly likes you, and probably wants to talk with you but is stumped as to what to say. I've been there.
You might make up some excuse to talk with him just to break the ice, like ask him some question. Just make sure it's open-ended, not a question he can answer with a simple yes/no or other canned answer. If you have any sort of shared experience with him like a class or event, you could ask him what he thinks about it, and share your thoughts too. Depending on the guy it may take a few repetitions of this before he relaxes enough to start initiating the conversations...some of us guys are pretty oblivious. :)
He could like you, but there are not enough signs, no one sign can tell you, you need to go off a collection of signs. I would read up about flirting body language on the internet and talk to him more and look for more signs before you make an assumption.