Absorptive surface area of the small intestine is greatly increased by the presence of

The epithelial cells that make up the small intestine are known as mucosa, and these mucosa have a variety of different layers that give rise to different functions. The mucosa's surface area is increased through villi, which are small circular folds that have finger-like projections. Microvilli are found on the mucosa's cell membrane  and they too are finger-like projections that increase the surface area even further.

answer: - b cells

explanation: -

there are many types of white blood cells present in our body. one such class of white blood cells are the lymphocytes. the b cells belong to the lymphocyte class of wbcs. the b cells perform their action against the pathogen by producing specialised proteins called as antibodies. these antibodies are produced as and when the b cells encounter pathogens in response to the antigens present on the surface of the pathogen. these antibodies bind to the antigens present on the pathogen and then, target them for destruction by other cells of the immune system.

so, the b cells mediate their action by identifying the antigens present on the surface of the pathogens and then producing antibodies in return to mediate its effect.