Answer: The correct answer is- C. Blood components are continuously produced in the bone marrow.
Formation of blood cells is a continuous process that occurs in the bone marrow ( a gelatinous, soft tissue present within bones) of adults.
This process is called as hematopoiesis, in which undifferentiated precursor cells ( also called stem cells) are developed and differentiated into particular blood cell type ( having specific function).
Thus, through this continuous process, all the components of blood can be replenished whenever they are required.
Therefore, when a person donates blood, he never run out of it.
