Shaggy and Scooby Could Not Figure Out Who the Masked

Shaggy and Scooby could not figure out who the masked intruder was from the clues that they found, so they decided to put the clues down and go to the kitchen for a few Scooby-snacks. After a couple of hours, Shaggy saw the clues again and realized who the masked intruder was. Shaggy solved this problem through

A) analogy.
B) incubation.
C) working backward.
D) decomposition.