The correct option is C HOW ARE YOU ?
15 will be decoded as O
23 will be decoded as W
Thus, first word will be 'HOW'
18 will be decoded as R
5 will be decoded as E
Thus, second word will be 'ARE'
25 will be decoded as Y
15 will be decoded as O
Thus, last word will be 'YOU'
Hence, the phrase will be decoded as "HOW ARE YOU"