What is the probability of choosing the correct answer at random from the options below.
a) 1/4
b) 1/2
c) 1
d) 1/4
If the answer is 1/4, then because 2 out of 4 answer choices are '1/4', the answer must actually be 1/2. This is a contradiction. So the answer cannot be 1/4.
If the answer is 1/2 (or 1), then because 1/2 (or 1) is 1 out of 4 answer choices, the answer must be 1/4. This is again a contradiction. So the answer cannot be 1/2 (nor 1).
So none of the provided answer choices are correct. Therefore the probability of choosing the correct answer is 0%