The correct answer is a) epithelial. Epithelial tissue is a type of tissue that forms a protective layer on body surfaces and serves as a lining for internal organs and cavities. This tissue type is characterized by closely packed cells that form continuous sheets, providing both protective and functional roles.
Epithelial tissue can be found in various forms throughout the body, including the skin (epidermis), the lining of the mouth, digestive tract, and respiratory system. It plays a crucial role in absorption, secretion, and sensation. In addition, epithelial cells can regenerate quickly, allowing the body to maintain its protective barriers and functions even after injury.