The correct answer is Oesophagus.

• An epithelial tissue or epithelium has a free surface, which faces either a body fluid or the outside environment and thus provides a covering or a lining for some part of the body.
• The cells are compactly packed with a little intercellular matrix.
• There are two types of epithelial tissues namely simple epithelium and compound epithelium.
  • Simple epithelium is composed of a single layer of cells and functions as a lining for body cavities, ducts, and tubes.
  • Compound epithelium consists of two or more cell layers and has a protective function as it does in our skin.
• Squamous epithelial cells are found in the inner lining of the oesophagus.

• On the basis of structural modification of the cells, the simple epithelium is further divided into three types:
  • Squamous:
    • The squamous epithelium is made of a single thin layer of flattened cells with irregular boundaries.
    • They are found in the walls of blood vessels, oesophagus, and air sacs of the lungs and are involved in functions like forming a diffusion boundary. 
  • Cuboidal:
    • The cuboidal epithelium is composed of a single layer of cube-like cells.
    • This is commonly found in ducts of glands and tubular parts of nephrons in kidneys and its main functions are secretion and absorption. 
  • Columnar:
    • The columnar epithelium is composed of a single layer of tall and slender cells.
    • Their nuclei are located at the base. 
    • They are found in the lining of stomach and intestine and help in secretion and absorption.