Select the letter-cluster that can replace the question mark (?) in the following series.
TXB, QWE, NVH, KUK, ?
Answer & explanation
Correct answer: option 1

Explanation:
TXB, QWE, NVH, KUK, ?
The logic followed here is :
T → (-3) → Q → (-3) → N → (-3) → K → (-3) → H
X → (-1) → W → (-1) → V → (-1) → U → (-1) → T
B → (+3) → E → (+3) → H → (+3) → K → (+3) → N
So, the letter-cluster that replaces the (?) to complete the series is "HTN'