Bertha Became Conditioned to Cry Every Time She Saw an Onion

Bertha became conditioned to cry every time she saw an onion chopper because she associated it with cutting onions, which always made her eyes water. For weeks, the onion cutter sat on the counter with no onions. Eventually, she never cried when she saw the cutter. Then the onion cutter disappeared for two months, and when Bertha saw it again for the first time, she began to cry. This response is known as

A) positive reinforcement.
B) negative reinforcement.
C) spontaneous recovery.
D) reconditioning.