Originally posted by Gobbah
From a logical standpoint, it's just meant to be a joke because 4 is not a letter, it's a number. There are so many examples of this and they were all intentional, just like the intentional change in the numbering system (note how it restarts at the Reasoning section but then continues on through at the Science section) and other questions that seem like "trick questions" are just meant to be completely, randomly stupid.
I know. I just felt like coming at the question from a logical standpoint. I was bored, only thing going for me was some music on Pandora and an empty water canister....