Which of the following statement$(s)$ is/are correct regarding compound epithelium?

• A
  It is made of more than one layer of cells and thus has a limited role in secretion and absorption.
• B
  Their main function is to provide protection against chemical and mechanical stresses.
• C
  They cover the dry surface of the skin,moist surface of buccal cavity,pharynx,inner lining of ducts of salivary glands and pancreatic ducts.
• D
  All of the above