The type of epithelial tissue that forms a single layer of flattened cells is

The correct answer is: simple squamous epithelium.

Explanation:

The epithelium is one of the four basic tissues found in the body, along with the connective tissue, the muscle tissue, and the nervous tissue.

Epithelial tissue is commonly found surrounding surfaces such as the skin, and also making up the inner lining of hollow organs such as the ones that form the gastrointestinal tract.

The number of layers and the shape of the cells in the epithelium have a direct correlation in the function of the tissue. Functions can vary a lot from organ to organ, from absorption to protection and everything in between.

A simple squamous epithelium is composed of a single layer of flat cells, which makes it permeable to liquids and small molecules, an important feature in organs where filtration or diffusion is needed; for example: capillaries and alveoli.