Which term defines a well tested, scientifically supported statement that explains how something works?

a. hypothesis
b. law
c. observation
d. theory

A law

Explanation:

A law is an explanation on the forces of nature that is tested so much its almost never to be found wrong.

hormones in blood stream

image: dtc.ucsf.edu

endocrine glands secrete hormones into the blood stream near them; the hormones then travel in our bloodstream until it reaches its destination, called a target cell, in distance parts of the body. in the target tissue, hormones lock onto the target’s plasma membrane, called the receptor site.