The correct answer is A. Phagocytosis.
Phagocytosis is a process by which cells engulf and destroy foreign particles, such as bacteria. It is one of the body’s first lines of defense against infection. Phagocytes are white blood cells that have the ability to move around and engulf foreign particles. Once a phagocyte has engulfed a foreign particle, it digests it using enzymes.
B cells, plasma cells, and T cells are all part of the adaptive immune system. The adaptive immune system is a more specific and long-lasting response to infection than the innate immune system. B cells and plasma cells produce antibodies, which are proteins that bind to and neutralize specific antigens. T cells help to regulate the immune response and kill infected cells.
Phagocytosis is a more primitive and nonspecific response to infection than the adaptive immune response. It is the body’s first line of defense against infection and is important for clearing away bacteria and other foreign particles. The adaptive immune response is a more specific and long-lasting response to infection. It is important for fighting off chronic infections and for protecting the body against future infections.