None
assumptions:
Spoiler
-"random" means our choice is a uniformly distributed random variable
-the problem can have at most one correct answer even if it is stated by many possible choices
(for example, the answer can't be both 50% and 25% but it can be both A and D)
(attempt at a) solution:
Spoiler
*Let's suppose that A is the correct answer.
Then D is the correct answer also, since they state the same thing.
Therefore, the chance of hitting a correct answer is .5. Therefore, B is the correct answer which is contradictory. So A can't be the correct answer.
*Under the same reasoning, D can't be the correct answer
*Let's suppose B is the correct answer.
Thus the chance of hitting a(the) correct answer is .25. Thus A or D is the correct answer, which is contradictory.
*same goes with C
Therefore none of the above answers is correct.
That was fun! (or might still be if I got it wrong!)
Are my assumptions wrong?
Is the solution wrong?