Using 'Respectively' in a form of a question

Respectively establishes a parallelism between two constructs or lists.

= in a way that relates or belongs to each of the separate people or things you have just mentioned

Cambridge

The exam question therefore asks you identify the option 1, 2, 3 or 4 that best matches the volatile/non-volatile pattern to the first/second terms of the option.

RAM is volatile: ROM is non-volatile; flash is non-volatile: magnetic is non-volatile. The option that parallels the volatile/non-volatile pattern set by “respectively” is thus 2.

If the word is omitted, the notion of parallelism is lost and there is ambiguity in the question. There is also obscurity, because it then asks what is volatile and non-volatile. Being opposites, there is nothing that fits such a definition!

In my opinion, this wording is somewhat awkward because of the use of the word 'a'. RAM and ROM are types of memory, but unless it's usage that I've just never seen, one would not say, "RAM is a volatile memory." That sounds like you're talking about a personal recollection to me. The use of 'respectively' is necessary, however, because of the way the answers are patterned. It feels like the question was written by someone whose first language is not English, although that may be a flawed impression. I think, ideally, this would be two separate questions, one about volatile memory, another about non-volatile.