Here, the terms of the given series are a combination of letters and numerals, which have according to a set pattern.

1)

C4X, F9U, I16R, ?


A) K25P

B) L25P

C) L25O

D) L27P

Answer:

Option C

Explanation:

1st letter : $C+3\rightarrow F, F+3\rightarrow I, I+3\rightarrow L$

Numbers : 4(22) → 9(32) → 16(42) → 25(52)

3rd letter : $X-3\rightarrow U, U-3\rightarrow R, R-3\rightarrow O$

Hence the answer is (c).