Read the passage and answer the question. The bone marrow produces millions of normal blood cells every day. These cells come in three varieties: red blood cells, white blood cells, and platelets. The red cells are important carriers, transporting oxygen to all body cells and removing waste products from the cells. White blood cells are the defenders of the body as they protect it from infection and illness. Platelets are small cells which help the blood to clot and prevent hemorrhages. 1 Select the correct answer. What does the author imply in this paragraph?

A. Normal production of blood cells is a necessity for a healthy body.
B. The bone marrow produces three types of blood cells.
C. The three varieties of blood cells are interdependent.
D. Great problems occur when the normal production of blood cells is interrupted.