Based on the English alphabetical order, three of the following four letter-clusters are alike in a certain way and thus form a group. Which is the one that does not belong to that group? (Note: The odd group 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 are alike in a certain way and thus form a group. Which is the one that 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.)

Four letter-number pairs are given. The letter-number on the left side of (-) is related to the letter-number on the right side of (-) following a specific logic. Select the odd one out. (NOTE: Operations should be performed on whole numbers without breaking them into constituent digits.)