In the letter pattern MN_NOM_OPM_OP_, which one set of letters, when inserted sequentially in the blanks, will correctly complete the series?

Introduction / Context:
This question is about completing a letter series where only three letters, M, N and O, plus P and Q appear repeatedly. The given pattern is written as MN_NOM_OPM_OP_, and we must choose a four letter sequence that, when filled into the blanks in order, produces a regular and meaningful structure. These problems typically hide overlapping sequences or repeated blocks, and the candidate's role is to reveal that hidden structure by trying each option systematically and checking for consistency.

Given Data / Assumptions:

• Incomplete pattern: M N _ N O M _ O P M _ O P _.• Four blanks must be filled using one of the given options.• Options supply letter sequences: MNNQ, MNOQ, MNPQ and MNOO.• The letters M, N, O, P and Q are expected to form a smooth overlapping series like MNO, NOP, OPQ and so on.

Concept / Approach:
Instead of guessing based on appearance, the best approach is to fill in each option and then examine the full string formed. We look for regular overlapping sequences where a block of letters such as MNO, NOP or OPQ appears again and again. The correct answer should produce a clean repetition of such blocks or at least a clear, almost mechanical sliding pattern, rather than an irregular jumble of letters.

Step-by-Step Solution:
Step 1: Fill the blanks with option a, MNNQ.Step 2: Insert the letters sequentially into the four blanks to get: M N M N O M N O P M N O P Q.Step 3: Now observe the pattern of overlapping triplets: MNM, N M N, M N O, N O M, M N O, N O P, O P M, P M N, M N O, N O P, O P Q.Step 4: Within this, repeated sliding segments MNO, NOP and OPQ appear regularly, indicating a meaningful and systematic structure.Step 5: Try alternative options briefly. For example, with MNOQ, the completed string includes awkward fragments like MOO and OOP that break the smooth sequence of consecutive letters.Step 6: Option MNPQ and MNOO similarly generate irregular letter combinations that do not produce a neat overlapping progression through M, N, O, P and Q.Step 7: Therefore, the only option that creates a strongly patterned series is MNNQ.

Verification / Alternative check:
Another way to see the regularity is to focus on the central region: after inserting MNNQ, we can see the subsequences M N O, N O P and O P Q appearing in order. These subsequences are constructed from consecutive letters in the alphabet and are a hallmark of well-designed verbal reasoning questions. The fact that they arise naturally from MNNQ and not from the other options confirms that this completion aligns best with the intended pattern of overlapping alphabetical progressions.

Why Other Options Are Wrong:
Option MNOQ produces stretches such as M O O and O O P which disrupt the flow of consecutive letters and create duplicated vowels in the centre. MNPQ introduces P too early and breaks the neat slide from M N O to N O P to O P Q. MNOO similarly distorts the sequence with repeated O letters in positions where we expect a clean alphabetic step. Because reasoning-series questions typically favour elegant and symmetric structures, these irregular sequences are much less plausible than the clear structure generated by MNNQ.

Common Pitfalls:
A frequent mistake is to consider only the first or last few letters and ignore the full pattern across the entire string. Another is to choose an option simply because it contains a familiar sequence such as MNO without checking the neighbouring overlaps. To solve such problems reliably, candidates should always build the complete series for each promising option and then look carefully for repeated, regular blocks that span the length of the pattern.

Final Answer:
MNNQ