Final answer:
Microfold (M) cells transport antigens from the gut to immune cells but are not phagocytic. They are protected by mucus not scattered in lymph nodes. The correct answer is b.
Step-by-step explanation:
Microfold cells, also known as M cells, are specialized epithelial cells found in the mucosal tissues such as the Peyer's patches of the small intestine. These cells are involved in the immune system's response to potential pathogens entering the gut. By transporting antigens from the intestinal lumen to underlying immune cells, they contribute to the body's immune surveillance. However, M cells are not phagocytic themselves; instead, they transport antigens to dendritic cells, which may then present these antigens to T cells and B cells in Peyer's patches or transfer them to mesenteric lymph nodes where an immune response is mounted.
Given the information, it can be concluded that M cells are: (a) not phagocytic, (b) are protected from digestive enzymes by a layer of mucus, and (c) are found within the Peyer's patches rather than scattered throughout mesenteric lymph nodes. Therefore, the correct answer with respect to M cells is b. They are protected from digestive enzymes by a thick glycocalyx and a layer of mucus, but they are not phagocytic or scattered throughout the mesenteric lymph nodes.