Cells Are the Smallest Independent Units of Life, and All

Multiple Choice

Cells are the smallest independent units of life, and all life as we know it depends on the many chemical activities of cells. Some of the basic functions of cells are growth, metabolism, irritability, and reproduction. Cells vary in size from a sperm, which is about 5 micrometers (five-millionths of a meter) long, to a nerve cell with thin fibers that may be more than a meter long. (Robert Carola, John P. Harley, and Charles R. Noback, Human Anatomy and Physiology, 2nd ed.)
This passage exemplifies a(n) _____.

A) report
B) explanation
C) argument
D) illustration
E) unsupported assertion