Which type of tissue primarily forms the outer layer of skin?

Epithelial tissue is the correct answer because it constitutes the outer layer of skin, known as the epidermis. This layer serves several vital functions, including protection against environmental hazards, regulation of moisture loss, and sensation. Epithelial cells are tightly packed, providing a barrier against pathogens and physical damage. Additionally, they play a key role in the skin's ability to regenerate and heal, as these cells can rapidly divide and migrate to repair any injuries.

Nerve tissue, connective tissue, and muscle tissue do not form the outer layer of the skin. Nerve tissue is involved in sensation and signal transmission but does not contribute to the skin's protective outer layer. Connective tissue, found in areas such as the dermis, supports and anchors the outer epidermal layer but does not form it. Muscle tissue is responsible for movement and is not involved in forming any part of the outer skin structure. Each tissue type has its specific function and location within the body, but in the context of the outer skin layer, epithelial tissue is the key player.