Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.NKY, LHU, JEQ, ?, FYI

Let's analyze the pattern element by element across the series:First letters: N, L, J, ?, F$\text{N (14)}-2=\text{L (12)}$$\text{L (12)}-2=\text{J (10)}$$\text{J (10)}-2=\text{H (8)}$$\text{H (8)}-2=\text{F (6)}$ Second letters: K, H, E, ?, Y$\text{K (11)}-3=\text{H (8)}$$\text{H (8)}-3=\text{E (5)}$$\text{E (5)}-3=\text{B (2)}$$\text{B (2)}-3=\text{Y (25)}$ Third letters: Y, U, Q, ?, I$\text{Y (25)}-4=\text{U (21)}$$\text{U (21)}-4=\text{Q (17)}$$\text{Q (17)}-4=\text{M (13)}$$\text{M (13)}-4=\text{I (9)}$ Combining the results, the missing letter-cluster is HBM.