Correct Option: A

Squamous epithelial cells have the appearance of thin, flat plates. The shape of the nucleus usually corresponds to the cell form and helps to identify the type of epithelium. Squamous cells, for example, tend to have horizontal flattened, elliptical nuclei because of the thin flattened form of the cell. They form the lining of cavities such as the mouth, blood vessels, heart and lungs and make up the outer layers of the skin.