Insert the five letters to complete the pattern without breaking the anchors. Series: _ bbca _ bcca _ ac _ a _ cb

Introduction / Context:
Another anchor-based completion: substrings like “bbca”, “bcca”, and “ac…cb” must be preserved. We insert five letters to keep those anchors intact and create smooth joins.

Given Data / Assumptions:

• Template: _ bbca _ bcca _ ac _ a _ cb
• Five blanks, one five-letter option, placed sequentially.

Concept / Approach:
Favor fills that maintain “bbca” then “bcca”, and finally produce a clean “ac…a…cb” ending, avoiding triple-letter collisions.

Step-by-Step Solution:
Insert "bacab": b bbca a bcca b ac a a cb. The anchors are preserved in order, and joins remain consistent without forced breaks.

Verification / Alternative check:
Competing fills either break “bcca” or leave an untidy tail before “cb”.

Why Other Options Are Wrong:
abeba / acbab / bcaajb: Each damages at least one anchor or creates awkward double a/b clusters at boundaries.

Common Pitfalls:
Not checking the last two joins; the final “…a _ cb” part is especially sensitive.

Final Answer:
bacab