Extinction occurs as behavior due to lack of reinforcement.
a. immediately stops
b. tends to fluctuate
c. gradually strengthens
d. gradually diminishes

The right option is; d. gradually diminishes

Extinction occurs as behavior gradually diminishes due to lack of reinforcement.  

Extinction is the gradual weakening of a previously learned behavior, due to lack of reinforcement which causes the behavior to decrease or disappear (eventually stops). Extinction can happen in all types of behavioral conditioning, but it is usually associated with operant conditioning (learning process through punishments and rewards for behavior).

the rebels’ chances of victory at lexington & concord were fairly slim, given the fact that most of them very untrained and they were up against the world's greatest military force.  

one way archaeology us understand the past is through the material objects it finds, allowing us to know what was being used, and when. for example a dig recently found a flute, believed to be the oldest musical instrument found to date.

i hope this