Which statement best defines simple epithelium?

• A. It has two or more layers.
• B. It has only one layer.
• C. It is typically found lining blood vessels.
• D. It contains goblet cells.

Answer: (B)

Simple epithelium is defined by its single layer of cells resting on the basement membrane, which allows efficient diffusion, absorption, and secretion. The statement that it has only one layer directly captures this definition, making it the best choice. Having two or more layers describes stratified epithelium, not simple. Lining blood vessels (endothelium) is an example of simple epithelium but isn’t by itself the defining feature, and goblet cells can be present in some simple epithelia but their presence does not define simplicity.