Explanation:

Let’s break it down piece by piece:

- Look at the series: ABDE, FGIJ, ?, PQST, UVXY

- Each cluster has four letters.

- Check the pattern by the position of letters in the alphabet:

- A(1), B(2), D(4), E(5)

- F(6), G(7), I(9), J(10)

- Notice how they skip a letter each time:

- (A) skip C, (B) skip nothing, (D) skip nothing, (E)

- But actually, (A)->(B): +1, (B)->(D): +2, (D)->(E): +1

- But the more reliable pattern is by starting position:

- First: A, F, K, P, U (A=1, F=6, K=11, P=16, U=21): all jump +5

- Now check the spread in each cluster:

- ABDE: 1(+1)2(+2)4(+1)5

- FGIJ: 6(+1)7(+2)9(+1)10

- So, same pattern!

- Now, the missing set:

- After F(6), add 5 ? K is 11

- Should be: 11 (K), 12 (L), +2 = 14(N), +1 = 15(O)

- But wait: using the same increments (+1, +2, +1): K(11), L(12), N(14), O(15)

- Now, check the options:

1. KLMO

2. KLNO

3. KLMN

4. KLNP

- From above, it should be KLNO.

KLNO is the right answer.

- Each group starts 5 letters ahead of the previous group.

- Each internal letter sequence moves: +1, +2, +1.

- Therefore, KLNO fits the pattern exactly.

- The other options either have the wrong letter skipped or mess up the order.

In short, you spotted the right pattern—KLNO. You're good.