In a code language, the word "BURN" is written as "YFIM" using a reverse alphabet (Atbash) substitution. Using the same coding scheme, what is the code for the word "WOUND"?

Introduction / Context:
This is a classic example of coding based on the reverse alphabet, also known as the Atbash cipher. Under this scheme, A is paired with Z, B with Y, C with X and so on, reflecting letters across the center of the alphabet. The question demonstrates this with BURN and asks for the corresponding code of WOUND.

Given Data / Assumptions:

• BURN is coded as YFIM.
• We must encode WOUND using the same substitution.
• Mapping pairs are A with Z, B with Y, C with X, D with W, E with V, F with U, G with T, H with S, I with R, J with Q, K with P, L with O, M with N, and vice versa.

Concept / Approach:
The Atbash mapping is symmetric. For each letter in BURN, we find its partner in the reversed alphabet and compare to the code letter. Once we confirm this mapping works for each position, we apply the same substitution to WOUND. The conversion is purely letter by letter, with no reordering or arithmetic involved.

Step-by-Step Solution:
Step 1: Write BURN and the coded word YFIM in parallel to confirm the substitution. Step 2: Under Atbash, B pairs with Y, U pairs with F, R pairs with I and N pairs with M. This perfectly matches BURN to YFIM. Step 3: Now apply the same mapping to WOUND. Step 4: W pairs with D, because D is the fourth letter from the start and W is the fourth from the end. Step 5: O pairs with L, since O and L are symmetric around the center of the alphabet. Step 6: U pairs with F, N pairs with M and D pairs with W according to the same rule. Step 7: Putting these together, W, O, U, N, D become D, L, F, M, W, giving DLFMW. Step 8: Therefore the code for WOUND is DLFMW.

Verification / Alternative check:
We can check the mapping for each letter independently. For instance, check that both B and Y sum to 27 when expressed as positions (2 plus 25). The same holds for W and D (23 plus 4), O and L (15 plus 12), U and F (21 plus 6) and N and M (14 plus 13). This constant sum property of 27 is another hallmark of the Atbash cipher and shows that the substitution is consistent.

Why Other Options Are Wrong:
DLFMD changes the last letter from W to D, breaking the Atbash pairing for D. DNFMW and DPFMW alter the middle letters, implying incorrect partners for O or U. None of these options maintain a proper reverse alphabet mapping for all letters of WOUND, so they cannot be correct under the established coding scheme.

Common Pitfalls:
Sometimes candidates try shifting letters forward or backward instead of using the exact reverse pairing, or they mistakenly map each letter using different rules. A systematic way is to write the full alphabet and its reverse beneath it, then directly map each letter. This consistency avoids confusion and ensures the correct code word is obtained.

Final Answer:
Using the reverse alphabet (Atbash) substitution, the correct code for "WOUND" is DLFMW.