In a mixed letter coding system, if 'CAT' is coded as 'DHW', what is the code for 'DOG'?
Answer: C. FQJ
The pattern shows that each letter is shifted by a certain number of positions in the alphabet. 'D' to 'F' is +2, 'O' to 'Q' is +2, and 'G' to 'J' is +2.