If N = 13 and L = 15, then NATIONAL =?

Correct option is D

GIVEN:
N=13
L=15
Logic: The code is the opposite letter's position. 
The patter followed here;

Write the position of the letter opposite to the letter
N = M 13 (as given)
A = Z 26
T = G 7
I = R 18
O = L 12
N = M 13 (as given)
A = Z 26
L = O 15(as given)
Now, substituting these values into "NATIONAL":
NATIONAL= 132671812132615