If amphetamines stimulate the central nervous system,what is the function of barbiturates?

Which of the following opium alkaloids is used for the relaxation of smooth muscles?

Heroin is extracted from which plant family?

Identify the correct statement.

Read the following statements:
$a.$ Heroin,commonly called smack,is obtained by acetylation of morphine.
$b.$ Cocaine is obtained from the latex of Papaver somniferum.
$c.$ Dopamine is an excitatory neurotransmitter.
$d.$ Morphine is an effective sedative and painkiller.
Mark the option which includes both correct statements.

From which plant parts are Bhang, Ganja, and Charas obtained?