Which letter will replace the question mark in the following circle?

Which letter will replace the question mark in the following circle?

Explanation
Which letter will replace the question mark in the following circle?

A. G
B. U
C. V
D. H

E (5) + O (15) = 20
D (4) + P (16) = 20
K (11) + I (9) = 20
L (12) + ____ = 20