Three of the following number pairs are alike in a certain way based on a logical rule. Select the option that is different from the other three.

Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which letter-cluster pair DOES NOT belong to that group? (Note: The odd one out is not based on the number of consonants/vowels or their position in the letter-cluster.)

Based on the English alphabetical order, three of the following four letter-cluster pairs are alike in a certain way and thus form a group. Which letter-cluster pair DOES NOT belong to that group? (Note: Positions of letters from the beginning and end are paired as opposites, e.g., Y-B, G-T, H-S, R-I; sum of positions = 27)