This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Endocrinology, Subject name: Physiology
The major regulator of platelet production is the hormone thrombopoietin (THPO), which is produced by 
Select and explain. 
A. Kidneys, B. Liver, C. Liver and kidneys, D. Spleen and lymph nodes
C: Liver and kidneys
Answer: C: Liver and kidneys 
Explanation: Thrombopoietin (THPO) also known as megakaryocyte growth and development factor (MGDF) is a protein that in humans is encoded by the THPO gene.Thrombopoietin is a glycoprotein hormone produced by the liver and kidney which regulates the production of platelets. It stimulates the production and differentiation of megakaryocytes, the bone marrow cells that bud off large numbers of platelets.Ref: Ganong&;s review of medical physiology;24th edition; page no-80