Study the given pattern carefully and select the letter that can replace the question mark (?) in it.

Correct option is B

Given: 

In this figural series following logic is  followed-  

First group: f → k → n

f (6th letter) → k (11th letter) → n (14th letter)

The pattern is an increase of +5, then +3.

Second group: u → z → c

u (21st letter) → z (26th letter) → c (3rd letter, wrapping around the alphabet)

The pattern is an increase of +5 (u → z) and then +3 (z → c, after wrapping around).

Third group: j → o

j (10th letter) → o (15th letter)

The increase is +5.

Following the consistent pattern of +5, +3:

The next letter after o (15th letter) should be r (18th letter, +3).

The letter that replaces the question mark is R.