How many such pairs of letters are there in the word ‘APPREHENSION’ each of the which has as many letters between them in the word as there are between them in the English alphabet ?

Here, we are required to find the pair of letters which have the same number of elements between them as in English alphabets.
So we can start with the first letter and check in the same manner. For example lets start with AP. Now in original english alphabets there are 14 letters between A and P. But here there is none, so this cannot be a possible pair. Similarly AR can also not be the pair since it has only two letter between A and R, whereas in original sequence it is way more than that. Moving forward AE meets the requirement since it has only 3 letters between A and E which is same as that in original alphabets. Checking in the similar manner we can find the required pair of words which satisfy the given condition are
PR
PI
HN
Thus there are 4 possible pairs which makes option 1 the correct choice.