Four letter-cluster pairs have been given, out of which three are alike in some manner and one is different. Select the one that is different.

Explanation

Rule: reverse the first three letters and the last three, apply +1, −1, +1 to each group, and keep the middle letter. COMMAND should give NND M EMB = NNDMEMB, but the pair shows NNDMENB. The other three pairs follow the rule.