A coding pattern alternates identity and +1 shift by position. If FATHER is coded as FBTIES (positions 1,3,5 unchanged; 2,4,6 shifted +1), what is the code for SISTER?

Introduction / Context:
Many coding-decoding questions use position-based rules rather than a single uniform shift. Here, the example FATHER → FBTIES shows that odd positions stay the same while even positions are advanced by +1 letter.

Given Data / Assumptions:

• Mapping demonstration: F(1)→F, A(2)→B, T(3)→T, H(4)→I, E(5)→E, R(6)→S.
• Rule: odd positions unchanged; even positions shifted forward by +1 (with wrap from Z to A if needed).
• Task: Apply to SISTER (6 letters).

Concept / Approach:
Process each letter by its 1-indexed position. Keep 1st, 3rd, 5th as-is; shift 2nd, 4th, 6th by +1.

Step-by-Step Solution:
1) S(1) → S2) I(2) → J3) S(3) → S4) T(4) → U5) E(5) → E6) R(6) → SHence, SISTER → SJSUES.

Verification / Alternative check:
Apply the pattern back to FATHER to confirm the rule matches exactly as shown in the prompt example.

Why Other Options Are Wrong:

• SKSVET / SHSSEQ / TJTUFS: These violate the odd/even position rule at one or more positions, using inconsistent shifts or altering odd-position letters.

Common Pitfalls:
Applying a uniform shift, using 0-indexed positions, or forgetting wrap-around behavior.

Final Answer:
SJSUES