What type of tissue covers both the internal and external surfaces of the body?

Epithelial tissue is the correct answer because it serves as a protective layer that covers the surfaces of the body, including both internal and external areas. This type of tissue is characterized by closely packed cells that form continuous sheets, providing a barrier to protect underlying structures and regulate the passage of substances. Epithelial tissue is also involved in absorption, secretion, and sensation, highlighting its essential roles in various bodily functions.

In contrast, connective tissue primarily supports and binds other tissues and organs together; it does not primarily serve as a covering. Muscle tissue is responsible for movement, and while it may form the bulk of certain structures like the heart and limbs, it does not cover surfaces. Nervous tissue is specialized for transmitting signals and does not fulfill the protective covering role of epithelial tissue. Thus, the unique properties and functions of epithelial tissue make it the appropriate answer for this question.