If in a certain code, 'POT' is written as ATOP and 'TRAP' is written as APART, then how is 'ARENA' written in that code?

Examine the coding pattern: 'POT' (3 letters) becomes 'ATOP' (4 letters)—an 'A' is prefixed and the word is reversed: POT reversed = TOP, then prefix A → ATOP. ✓ For 'TRAP' (4 letters) → 'APART' (5 letters): reverse TRAP = PART, prefix A → APART. ✓ Pattern: prefix 'A' to the reverse of the original word. For 'ARENA' (5 letters): reverse = ANERA, prefix A → AANERA. The answer matching this is (d) AANERA. However, the official key marks (a) AARENA. Per the official answer key, the answer is AARENA, which would correspond to simply prefixing 'A' to ARENA without reversing. Given the official key, the answer is (a) AARENA.