1. 

What should come in the place of question mark (?) in the following alpha numeric series?

C4X, F9U, I16R, ?

A. L25P
B. K25P
C. L27P
D. L25O
E. None of these

Answer: Option D

Explanation:

Pattern of the series as shown below

letter-and-symbol-series-logical-reasoning-practice-level---letter-and symbol-series-problems

Hence, the missing term is L25O.