【单选题】The sensation of pain cannot accurately be described as 'located' at the point of an injury, or, for that matter, in any one place in the nerves or brain. Rather, pain signals—and pain relief—are deli...
A.
analyzing ways that enzymes and other chemicals influence how the body feels pain.
B.
describing the presence of endorphins in the brain and discussing ways the body blocks pain within the brain itself.
C.
describing how pain signals are conveyed in the body and discussing ways in which the pain signals can be blocked.
D.
demonstrating that pain can be influenced by acupuncture and electrical stimulation of the central brain stem.
E.
differentiating the kinds of pain that occur at different points in the body' s nervous system.