Which of the following best describes how psychoactive drugs affect the brain?

Which of the following best describes how psychoactive drugs affect the brain?

Select one:

a. They cause new neural connections to be formed that produce new neurotransmitters

b. They change the types of neurotransmitters that are released

c. They alter the amount and/or action of the various neurotransmitters

d. They create new neurotransmitters