Researchers condition a flatworm to contract its body to a light by repeatedly pairing the light with electric shock. The stage in which the flatworm's contraction response to light is established and gradually strengthened is calledA) discrimination. B) acquisition. C) generalization. D) spontaneous recovery.

Answer: Acquisition

Explanation:

The stage at which the flatworm contracts its body in response to light with electric shock is established and it is gradually strengthened is known as acquisition.

It can be demonstrated as an act of increasing the strength of the conditioned response in successive trails by pairing the conditioned stimuli and unconditioned stimuli.

Hence, the correct answer here is acquisition.