The correct option is A b
A conjunction combines or connects two sentences as one, it may be one word or a pair of words, the pair of conjunctions is called 'correlative conjunctions' as they have a combined function. 'Neither...' is a correlative conjunction, and there's an error in the sentence. 'Neither' as a conjunction connects two or more negative alternatives, 'neither' is only paired with 'nor', and 'either' with 'or'. Here the (b) part of the sentence contains 'or' even though the conjunction 'neither' is present, and the sentence refers to two negative alternatives. Hence 'or' is the error here, and (b) has the error, hence we choose option B. (A) has no error, as the alternatives "favour of arms" and "favour of nuclear disarmament" are in the negative, a choice can't be made in the positive, as both choices are in terms of warfare, it can't be one or the other, but none, so this part is grammatically correct. Hence we don't choose option A, it does not have an error. (C) has no error, it's grammatically correct with the adjectives "simple nuclear" and the noun that it modifies "disarmament", hence we don't choose Option C. As the sentence has an error, the "No error part" cannot be chosen, in turn option D is not chosen.