Frank Lost a Contact Lens in His Kitchen; He Searches

Frank lost a contact lens in his kitchen; he searches for it by examining each linoleum tile in turn to see if the lens is contained within the square. Gemma lost a lens in her kitchen; she looks for it near the base of the fridge and around the stove because these are the two appliances she remembers using when she was last in the kitchen. Which of these individuals is using a heuristic?

A) Only Frank is using a heuristic.
B) Only Gemma is using a heuristic.
C) Both Frank and Gemma are using heuristics.
D) Neither Frank nor Gemma is using a heuristic.