Answer:
d. a system that enhances the destruction of bacteria through the activation of mast cells, lymphocytes, and phagocytes
Explanation:
Mast cells are white blood cells (i.e., lymphocytes) that form part of the immune system. These cells form part of the first line of defense against pathogenic organisms. Some of the most important phagocytic cells that function to protect the body by ingesting pathogenic agents (e.g., harmful bacteria) include mast cells, monocytes, neutrophils, macrophages and dendritic cells. In this regard, it is important to highlight that mast cells are similar to basophil granulocytes (another type of lymphocyte), and they are derived from hematopoietic stem cells.