Since the correct mathematical answer isn't one of the options, the people picking the other options are representing a real resistance to the order of mathematical logic that binds us.
The real answer is 14 because I'm 14 and this is deep.
For me it's 13 because it's the "wrongest" one. Every single number in the term is even so you'd expect people to at least choose something that is even, too. Not only is 13 odd, it's a friggin prime..