Why is it important to have rest periods between sets of an exercise or workout? in order to free up time to work on other activities in order to measure one's heart rate in order to prevent the risk of muscle strain and injury in order to ensure breakdown of muscle protein?

i think it's c

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.