Fill in the blanks in the letter pattern: _po_mp_n__onmpo_.

Introduction / Context:
This reasoning question involves a patterned string of letters with several blanks represented by underscores. You are required to choose a group of letters that, when inserted into the blanks in order, produces a meaningful and regular repetition of a smaller pattern. This tests attention to detail and pattern recognition in sequences of letters.

Given Data / Assumptions:

• Base pattern with blanks: _po_mp_n__onmpo_
• Each option is a six letter string that will fill the six underscores in order.
• The final word like string should display a regular repeating pattern such as mpon or mpom.

Concept / Approach:
The idea is to substitute each candidate string into the pattern and observe the resulting continuous sequence. The correct option will usually create repeated segments with a stable structure, often a small block of letters appearing several times, while wrong options produce irregular or broken patterns.

Step-by-Step Solution:
Step 1: Remove the blanks in the base pattern to see fixed letters: p o m p n o n m p o. Step 2: Note that the substring mpon is present and likely to repeat. Step 3: Try option C, mnompn, by filling the blanks from left to right: Position 1: m, positions 4 and 7: n and o, positions 9 and 10: m and p, last position 16: n. Step 4: The completed string becomes mpommponmponmpon. Step 5: Group this as mpom | mpon | mpon | mpon. Here the repeated block mpon appears three times at the end, and the initial block mpom is just a slight variation that smoothly leads into the repeating pattern.

Verification / Alternative check:
When we test other options, the resulting strings are irregular. They fail to produce clear repeated segments, and the arrangement of m, p, o, n letters looks random. Option C, however, gives a tidy structure where a core pattern mpon repeats three times at the end, which is exactly the kind of regularity expected in exam puzzles of this form. This strong repetition is a clear indicator that option C is intended.

Why Other Options Are Wrong:
Using opmpnm, mponpo, or mnopnm creates awkward combinations where letter groups do not repeat in any simple consistent way. The sequences contain mismatched fragments like opop or ppn that do not suggest a designed pattern. Without a clean repetitive block, those options are unlikely to be the correct completion of the series.

Common Pitfalls:
Some students attempt to read a meaningful word, which is not necessary here and can be misleading. Others only test the first couple of positions and decide too early. The correct method is to fully substitute each candidate and then search for repeating patterns that look deliberate rather than accidental.

Final Answer:
The six letter string that correctly completes the pattern is mnompn.