If MENTOR = NVMGLI Then PROFESSOR = A. QSPGFTTPS B.KILUVHHLI C.KSLGVTHMI D. KILGFHHLI

Each letter is replaced by its opposite letter in the alphabet (A↔Z, B↔Y, …; positions add up to 27): M↔N, E↔V, N↔M, T↔G, O↔L, R↔I gives NVMGLI. For PROFESSOR: P→K, R→I, O→L, F→U, E→V, S→H, S→H, O→L, R→I = KILUVHHLI.