Select the option that represents the letters that, when sequentially placed from left to right in the blanks below, will complete the letter series.
JJ_K_LM_N_ _ O _ _ Q _ R _

Let's count the elements and observe repeating blocks or continuous alphabetical sequence.
The template is: JJ _ K _ LM _ N _ _ O _ _ Q _ R _

Let's test Option C (KLNOPPQRS):
Blanks filled in order: K, L, N, O, P, P, Q, R, S
Inserting these into the blanks:
JJ (K) K (L) LM (N) N (O) (P) O (P) (Q) Q (R) R (S)

Let's look at the grouped pattern:
JJKK, LLMM, NNOO, PPQQ, RRSS... wait, let's write it down carefully:
JJ K K
L L M M
N N O O
P P Q Q
R R S (if the last blank is S)

Let's check the position alignment exactly:
Template: JJ [1] K [2] LM [3] N [4] [5] O [6] [7] Q [8] R [9]
Let's see if Option C fits:
1st blank = K → JJ K K
2nd blank = L → L LM
3rd blank = N → N N
4th blank = O → O
5th blank = P → P O
Let's re-verify the counting.

Let's write out the continuous pairs:
JJKK LLMM NNOO PPQQ RRSS
Total letters: 20 letters.
Let's check the letters in this sequence:
J J K K L L M M N N O O P P Q Q R R
Let's match with blanks:
JJ _ K _ LM _ N _ _ O _ _ Q _ R _
1st blank: K → JJ K
Then K
2nd blank: L → L LM
Then M
3rd blank: N → N N
4th blank: O → O
5th blank: P → P O? No, our target is JJKKLLMMNNOOPPQQRRSS.
Let's align it:
Position: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Target: J J K K L L M M N N O O P P Q Q R R S S
Template: J J _ K _ L M _ N _ _ O _ _ Q _ R _
Let's fill the blanks using the target:
3: K
5: L
8: M
10: N
11: O
13: P
14: P
16: Q
18: R
19: S is missing from template? Let's check template characters:
1=J, 2=J, 3=, 4=K, 5=, 6=L, 7=M, 8=, 9=N, 10=, 11=, 12=O, 13=, 14=, 15=Q, 16=, 17=R, 18=_
Blanks to fill: 3, 5, 8, 10, 11, 13, 14, 16, 18.
Values from target:
3 → K
5 → L
8 → M
10 → N
11 → O
13 → P
14 → P
16 → Q
18 → R

So the filled series is K, L, M, N, O, P, P, Q, R.
Let's check Option A: KLMNOPPQR.
This perfectly matches!