The given series is alphabetical in nature. To understand the pattern, we need to look at the positions of these letters in the English alphabet.

In the first letter of each pair: A, C, F incrementally changes according to +2, +3; thus the next in the series would result in +4, giving J.

In the second letter of each pair: Z, X, U decrementally changes according to -2, -5; thus the next in the series would result in -8, giving Q.

So, the correct answer is JQ (Option 1).

About the other options:

Option 2 (KP): This does not follow the rule of +2, +3 and -2, -5 in the positions of the letters in the alphabets.

Option 3 (IR): This does not comply with the rule of increment and decrement mentioned above.

Option 4 (IV): Even though there is an I, it doesn`t follow the decrement rule in the second letter, thus it cannot be the correct pair.