0% chance. Answering randomly may give you a result that coincidentally matches the truth, but you have provided no logical or epistemological support for your

0% chance. Answering randomly may give you a result that coincidentally matches the truth, but you have provided no logical or epistemological support for your choice, nor any chain of reasoning that leads you from the available evidence to a conclusion that there even is a correct answer. You have a 25% chance of randomly choosing the "right" answer, (C) 0%, but no paradox is created because you answered without establishing knowledge of the answer, and therefore your answer cannot rightly be called correct.