Concept:Each letter in the word is replaced by the letter immediately before it in the alphabet.Explanation:BIRD becomes AHQC: B → A, I → H, R → Q, D → C.So the rule is to subtract 1 from the position of each letter.Apply to FISH: F (6) → E (5), I (9) → H (8), S (19) → R (18), H (8) → G (7).Thus, FISH is coded as EHRG.
