[ Link doesn't know what "five-six" is. Hyrule uses the metric system! (Really, as in like, officially.) But it is nevertheless clear to him that Dark is sticking with his "little" accusation. Link isn't particularly insecure about his height, but he does get a little defensive when people point it out. His size doesn't stop him from doing what he needs to do and he doesn't like the idea of being judged for it.

Frowning, he lowers the ear of corn from his mouth. ]

My name is Link. Member of the Royal Guard of Hyrule, escort of Princess Zelda, and the Hylian Champion. I can handle myself. [ Even if he's little! ]