Examine this via a process of elmination:-
Parallel connection means any answer with 24 volts is wrong, so rule out c) and d) straight away. Now we've narrowed the choices by 50% just on simple logic!
A single battery rated at 12 V and 40Ah would "produce" 40 amps when discharged at 1 amp but we have two in parallel so answer b) is less "correct" than answer a).
By this process you arrive at answer a), even without the actual discharge rate being given.
Examiners who set such questions should themselves be subject to examination. I have sat many multiple-choice exams over the decades and even today these badly-worded questions still keep cropping up. Someone ought to write a book about them! (Not me, though, I've finished with exams of an academic nature now.)