The brain's own natural production of endorphins is likely to be suppressed by

A) physical pain.
B) physical exercise.
C) heroin use.
D) antidepressant drugs.

Endorphins

Naturally occurring peptides in the brain that act as neurotransmitters, known to relieve pain and induce feelings of pleasure or euphoria.

Heroin Use

The act of consuming heroin, an illegal opioid drug, which can lead to severe physical and psychological dependence and health issues.

Physical Exercise

Refers to any bodily activity that enhances or maintains physical fitness and overall health and wellness.