Which major tissue category includes tissues that function in secretion, absorption, and filtration?

Epithelial tissue covers the body surface and forms the lining for most internal cavities. The major function of epithelial tissue includes protection, secretion, absorption, and filtration.

Explanation:

Epithelial tissue spreads throughout the body surface covering line body cavities and hollow organs which form the major tissue in the glands. Epithelial tissue covers the outside of the body and lines organs, vessels, and cavities. Endothelium joins with the inner tissue lining which covers the brain, lungs, skin, and the heart. It acts as a barrier protecting the body and the environment and maintains the process of protection, filtration, absorption, excretion, and sensation.  Covering and lining epithelium and the Glandular epithelium which helps in surrounding the glands within the body surface are the characteristics feature in the human body.