Every Time Maricella Goes to Work in the Morning, She

Every time Maricella goes to work in the morning, she notices that her dog sulks in the corner of the room and looks very sad. Over several weeks, she notices that the dog gets unhappy when she picks up her car keys, immediately before leaving the house. Which phenomenon of learning best describes the dog's behavior?

A) classical conditioning
B) innate learning
C) punishment by removal
D) instinctive drift