So, you have to choose the answer at random, and the question had answers A-D (with no repeat answers and at least one of the options were correct) then your chances would be 25%.

So, now we have our answer. With 4 answers that do not repeat and one of them being the correct answer, then the answer is 25%.

However, in our scenario there is a repeat in the answers A-D.

Here is where it gets tricky. We could now say, if you picked one at random from these 3 options, (because one is a repeat which means there are either 2 correct options or 2 wrong options) and thus your chance of picking the right one is 33%.

But, if we assume that the rules are different. In the way that you figure out its 25% for a question with no repeat questions and one correct answer, and we exclude the answers the question before us from that analysis, then we would have a 50% chance of picking the right letter. However, that would only be true if despite them having the same exact content, there was still some arbitrary right letter.

So, I think this isn't a paradox so much as the muddling of underlying assumptions.

The question should read " If you choose an answer to this question at random and the question has 4 options, no repeated answers and there is a singular correct option, what is the chance you will be correct?"

The way it is phrased now leaves too many questions like can you repeat the answer in different options and if so, will they both be right?,