If SUN is coded as SVM, then TON will be coded as

Given: If SUN is coded as SVM.

Logic: 1st letter is same, 2nd letter + 1 and 3rd letter - 1 place.

For, SUN - SVM

S - S, U + 1 = V, N - 1 = M

Similarly,

TON - ?

T - T, O + 1 = P, N - 1 = M

So, TON is coded as TPM.

Thus, correct option is (a).