Which letter replaces the question mark?

Explanation:

From the given figure,

6²=36 – 44 = 36 – 16 = 20 and S is at 20 – 1 = 19^th position

4² – 17 = 16 – 7 = 9 and H is at 9 – 1 = 8^th place.

8² – 510 = 64 – 14 and M is at 14 – 1 = 13^th place.

Similarly, 5² – 25 = 25 – 10 = 15 and 15 – 1 =14.

14^th place is occupied by N because M is 14 and N comes after M in alphabetic series.

Hence, N replaces question mark.

Final Answer:

Hence, correct option is B i.e., N.