The position of '4' in the code is the same as the position of the letter 'R' in both words. So, the letter 'R' has code '4'. ⇒ The code for each letter in the given word is the number in the same position in its code. Hence, the codes for all the letters can be decoded as follows:-
Letter
Code
T
2
R
4
A
6
I
3
N
8
G
7
O
9
W
1
So, the code for 'RING' = '4387' (R - 4, I - 3, N - 8 and G - 7) Hence the correct solution is "4387".