The question is incomplete as it does not have the options which are:
a. primary
b. negative
c.positive
d. secondary
Answer:
A) primary
Step-by-step explanation:
In psychology, a reinforcer refers to a stimulus which strengthens the behaviour and increases the chances or probability of the desired response.
The reinforcer can be of two types on the basis of pairing with a stimulus as a primary reinforcer and secondary reinforcer.
The primary reinforcer refers to the stimulus which is present in the humans from birth and is evolved as a part of the evolution for survival. The primary reinforcer does not depend on the stimulus and therefore is considered unconditioned reinforcer. Since it has evolved as part of the evolution for survival, therefore, strengthen the behaviour such as sex, hunger, water, touch.
Thus, A) primary is the correct answer.