Explanation:

568

SHADOW is coded as 184 and TEDIOUS is coded as 384
The pattern followed here is :
Sum of the place value of reverse alphabets of the alphabets in a given word.
Reverse value = 27 - place value of alphabet
SHADOW = 8 + 19 + 26 + 23 + 12 + 4 = 92
TEDIOUS = 7 + 22 + 23 + 18 + 12 + 6 + 8 = 96
Similarly,
VALIDATE = 5 + 26 + 15 + 18 + 23 + 26 + 7 + 22 = 142
Hence, Option C is correct.