In a certain code language, if GREEN is coded as TIVVM, then how is PARTY coded in that language?

Correct option is D

The pattern follows a reverse alphabetical order (also known as opposite letter pairs), where each letter is replaced by the letter occupying the same position from the opposite end of the alphabet.
A ↔ Z (1st from start/end)
G ↔ T (7th from start/end)
R ↔ I (18th from start / 9th from end)
E ↔ V (5th from start/end)
N ↔ M (14th from start / 13th from end)
"GREEN" to "TIVVM":
G becomes T
R becomes I
E becomes V
E becomes V
N becomes M
Applying the Pattern to "PARTY":
P becomes K (16th from start / 11th from end)
A becomes Z (1st from start/end)
R becomes I (18th from start / 9th from end)
T becomes G (20th from start / 7th from end)
Y becomes B (25th from start / 2nd from end)
Thus, PARTY is coded as KZIGB