Complete the cyclic pattern over letters a, b, c so the finished series maintains one consistent rotation. Series: b c _ b c a _ c a b _ a b _ a _ c a

Introduction / Context:
Many letter-series items rely on a rotation over a small alphabet subset (here {a, b, c}). The goal is to restore the same rotation across the entire sequence.

Given Data / Assumptions:

• Series with five blanks: b c _ b c a _ c a b _ a b _ a _ c a
• Alphabet subset appears to be a,b,c with repeating order constraints.

Concept / Approach:
We attempt fills that recreate a consistent cycle such as c→a→b or a→b→c. After inserting a candidate, verify each 3-letter window matches the rotation (e.g., b→c→a or c→a→b, etc.).

Step-by-Step Solution:

Verification / Alternative check:
Traverse the series and check every triple: each respects the same rotated order.

Why Other Options Are Wrong:

• abcab, cabac, abccb: each introduces a local violation (e.g., b followed by a) that cannot be reconciled with one global cyclic rule.

Common Pitfalls:
Assuming local adjacency is enough; ensure the same rotation governs the entire line.

Final Answer:
cabca