Correct option is C

A + 12 = M; M + 12 = Y; Y + 12 = K; K + 12 = W
2nd letters: C → O → A → M → ?
C + 12 = O; O + 12 = A; A + 12 = M; M + 12 = Y
3rd letters: Y → K → W → I → ?
Y + 12= K; K + 12 = W; W + 12 = I; I + 12 = U
Final term = WYU
Thus, the correct option is (c) WYU