11. under what conditions can spontaneous recovery occur?
a) as a result of latent learning
b) when the conditioned stimulus starts again
c) after systematic desensitization
d) when the unconditioned stimulus is extinguished

D: When the unconditioned stimulus is extinguished

Explanation:

i would say the prokaryotic cells the prokaryotic cells are less complex, are usually found only in unicellular organisms and have more limited capabilities than eukaryotic cells.