Why.. that would depend on how many correct answers there were. If there were 4 correct answers, you'd have 100% chance. If there were 3, and you only had to pick one, then you'd be at 75% chance and so forth.
considering that all the answers seemed wrong logically, the chances would be 0%, but that's not an answer.
oh yeah.. i should write down the logic behind it before i forget. Logically, since there are 4 answers, you would have a 25% chance of guessing the correct answer; however, there are two 25% answers (A and D) so that would make 50% the correct answer (2 correct answers out of 4) which is B, but since B is only one out of 4 answers, you're back to 25% again. Contradictions in the answers make the chances of getting the right answer 0% since contradictions can not exist if there is to be one correct answer.