In a certain code language, BRIGHT = THGIRB and DARK = KRAD. What is the code for LIGHT?

Given: 

In a certain code language, BRIGHT = THGIRB and DARK = KRAD.

Logic: Letters are written in reverse order. (Backward direction)

For, BRIGHT = THGIRB

Reverse order: T, H, G, I, R, B

For, DARK = KRAD

Reverse order: K, R, A, D

Similarly,

LIGHT = ?

Reverse order: T, H, G, ​I, L

So, LIGHT = THGIL

Thus, correct option is (a).