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 excitatory neurotransmitter.
$d.$ Morphine is an effective sedative and pain killer.
Mark the option which includes both correct statement

• A

  $(a) \;\& \;(b)$

• B

  $(b) \;\& \;(c)$

• C

  $(c) \;\& \;(d)$

• D

  $(a) \;\& \;(d)$