Ertha 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

The answer is c. spontaneous recovery.

Explanation:

In classical and operant conditioning, spontaneous recovery refers to the sudden reapparition of the response to a stimulus, even when it was believed  to be extinct. Spontaneous recovery usually occurs after a period in which the conditioned stimulus was not present, as in the example.

This phenomenon is important to understand that an extinct behaviour is not the same as an unlearned behaviour.

answer; i believe its (transgender);

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals