Select the letter-cluster from among the given options that can replace the question mark (?) in the following series.
BOY, FMU, ?, NIM, RGI

BOY, FMU, ?, NIM, RGI

Logic: 1st +4, 2nd - 2 and 3rd - 4

First Letters:

B + 4 → F

F + 4 → J

J + 4 → N

N + 4 → R

Second Letters:

O - 2 → M

M - 2 → K

K - 2 → I

I - 2 → G

Third Letters:

Y - 4 → U

U - 4 → Q

Q - 4 → M

M - 4 → I

The missing letter-cluster is JKQ.

Thus, correct option is (d).