Saw that today on Reddit and read through the explanations given by serious math people. The answer, as I understand it, is

None of the above. The simplest explanation is as follows: on a random question with four different answers, guessing at random would get you a 25% chance of a right answer. So it might seem that the right answer is 25%. But there are two answers of 25% to this specific question. So that means your percent chance of guessing the answer "25%" to this specific question is actually 50%. Which means that for this specific question, the answer would be 50%... except that random guessing would only give you a 25% chance of guessing "50%..." which means that "50%" isn't the right answer. 60% is essentially there as an extra bonus "screw you" to your brain.