Select the option that is related to the third term in the same way as the second term is related to the first term.

FRONTIER : GSNOUHDS :: CLOSING : ?

DMNTHOH

A   B   C    D   E    F   G    H    I    J    K    L   M

 ↓    ↓    ↓    ↓    ↓     ↓   ↓    ↓     ↓   ↓    ↓    ↓    ↓

 Z   Y    X   W   V    U   T    S    R   Q   P    O   N

26  25  24  23  22  21  20  19  18  17  16  15  14

******************************************

FRONTIER : GSNOUHDS :: CLOSING : ?

The  logic followed here is :

CONSONANTS ARE ADDED +1

VOWELS ARE -1

F → (+1)→ G

R → (+1)→ S

O → (-1)→ N

N → (+1)→ O

T → (+1)→ U

I → (-1)→ H

E → (-1)→ D

R → (+1)→ S

SIMILARLY

C → (+1)→ D

L → (+1)→ M

O → (-1)→ N

S → (+1)→ T

I → (-1)→ H

N → (-1)→ O

G → (-1)→ H