Prove that either
a) this problem is solvable
or
b) this problem is unsolvable
Lets translate the instruction first.
"prove that either" = "explain why"
"this problem is solvable" = "there is an achievable solution"
"this problem is unsolvable" = "there is no achievable solution"
Now lets look at the question again. It asks to choose and explain either (a) or (b).
The answer is most definitely (a). No matter whether you say this problem is solvable or not, you've just answered the question. If you think there is no basis for the question then it isn't solvable so you answer (b). If you say it is a real question then you choose (a). The thing is, as long as you choose an answer, then you have just given your solution to the problem.Therefore you have just solved it! If you are still confused, think of it this way; You are asked to choose between 2 possible answers. You can't choose answer (c) because there is none. So no matter if you think whether this problem is solvable or not, as long as you think of either, you just solved it! You can not say that this is not a "problem" because this is a situation of which the solution is unknown. So it doesn't matter whether it is impossible to achieve a solution or not; as long as there is none, it's a problem. So the solution is (a)