What type of tissue is responsible for covering the body's surfaces and lining its cavities?

Epithelial tissue is the correct choice because it serves as a protective barrier that covers the body's outer surfaces, such as the skin, and lines internal cavities and passageways, including those of the digestive, respiratory, and urinary systems. This type of tissue is characterized by closely packed cells with minimal extracellular matrix, which allows it to create effective barriers and control the exchange of materials.

Epithelial tissue also has various functions that include absorption, secretion, sensation, and filtration, depending on its location and structure. For example, the epithelial lining of the intestines is specialized for absorption, while the skin provides a protective layer against environmental threats.

In contrast, connective tissue primarily provides support, binds other tissues together, and stores energy, but does not cover surfaces or line cavities. Nervous tissue is essential for transmitting signals throughout the body and facilitating communication, while muscle tissue is involved in movement. Each of these other types of tissue plays distinct roles but does not fulfill the specific functions of covering and lining that are characteristic of epithelial tissue.