If "LOFTY" is coded as "LPFUY" by keeping letters at odd positions unchanged and shifting letters at even positions forward by 1 (O->P, T->U), then how will "DWARF" be written?

Introduction / Context:
This positional coding rule alters only the even-indexed characters by a +1 shift while leaving odd-indexed characters unchanged. "LOFTY" -> "LPFUY" demonstrates this pattern.

Given Data / Assumptions:

• Positions counted from 1 on the left.
• Odd positions unchanged; even positions shift forward by 1.
• Alphabet wraps after Z if required.

Concept / Approach:
Apply the rule per position to "DWARF".

Step-by-Step Solution:
1 D (odd) -> D2 W (even) -> X3 A (odd) -> A4 R (even) -> S5 F (odd) -> FThus, code = DXASF.

Verification / Alternative check:
Check "LOFTY": L stays, O->P, F stays, T->U, Y stays, giving LPFUY as provided.

Why Other Options Are Wrong:

• DXBSG / DXATF / DWBSG: these modify odd positions or apply mismatched shifts to even positions.
• None of these: Not applicable since DXASF is valid.

Common Pitfalls:
Starting index from 0, or applying the shift to all letters rather than only even positions.

Final Answer:
DXASF