(Note: The odd one out is not based on the number of consonants/vowels or their position in the letter-cluster.)
The question asks to find the letter-cluster pair that does not follow the same pattern as the others, based on English alphabetical order. We need to analyze the relationship between the letters within each pair and between the two clusters in each option.
Let's determine the alphabetical position difference between the letters in each cluster:
The pattern here is +3 for the first cluster and +6 for the second cluster.
Both clusters show a difference of +3.
Both clusters show a difference of +3.
Both clusters show a difference of +3.
Options 2, 3, and 4 share a common pattern: the difference between the letters in the first cluster is +3, and the difference between the letters in the second cluster is also +3.
Option 1 (UX−XD) differs because while the first cluster (UX) has a difference of +3, the second cluster (XD) has a difference of +6 (wrapping around the alphabet).
Therefore, the letter-cluster pair UX−XD does not belong to the group.