Explanation:

Let’s break this down step by step.

Here’s the original series:

MNB_CM __ WCMNB __ M __ YC

- If you look closely, "MNB" shows up at the beginning. Then you see "_CM", then blanks, then "WCMNB".

- After "WCMNB" there are more blanks and then “M__YC”.

Let’s look at the options:

Option 1: V N B X C N B

- Plugging these in: MNBVCM N WCMNBBMXYC

- The sequence feels off—it doesn’t line up with the repeating bit we saw (“MNB”, “WCMNB”).

- "V" and "X" don’t fit the pattern.

Option 2: V N B Y O N B

- Inserting these: MNBVCM N WCMNBBMYYC

- Again, adding "V" and "Y" seems weird—no clear pattern connections.

Option 3: W Y Y Y C N B

- With these: MNBWCM Y WCMNBYMYYC

- Now this at least puts "W" right before the "CM," which is similar to what’s in “WCMNB.”

- “Y” fills could relate to the ending “YC.”

Option 4: W N B Y O N B

- Plug in: MNBWCM N WCMNBBMYYC

- This fits almost perfectly: You get "MNB," then "WCM," then "NB," and it lines up with the repeated "N B" at the end.

- Also, the ending pieces ("B M Y YC") flow well with the original fragment.

Here’s the thing:

The correct pattern here is that the string “WCMNB” repeats, and the missing letters need to keep that repetition going.

Option 4 first fills the blanks with exactly the letters needed to keep the original repeating pattern, both at the start and end. It matches the recurring elements in the sequence ("MNB", "WCMNB", etc.).

So the correct answer is:

Option 4: W N B Y O N B