Throughout the Day, Activities in the Liver, Kidneys, and Endocrine

Multiple Choice

Throughout the day, activities in the liver, kidneys, and endocrine glands undergo large changes. Body temperature, blood pressure, and amino acid levels also shift from hour to hour. In fact, people tend to be more energetic and alert when these and other activities are at their highest point once a day. This is a description of

A) the Yerkes-Dodson law.
B) sensation-seeking patterns.
C) circadian rhythms.
D) biological condensation.