In adults, the only site of red blood cell production, and the primary site of white blood cell formation, is the
A) liver.
B) spleen.
C) thymus.
D) red bone marrow.
E) yellow bone marrow.
Question 2
The vitamin that is part of the coenzyme NAD is
A) thiamine.
B) riboflavin.
C) niacin.
D) folic acid (folate).
E) cobalamin.