This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Adrenal Gland, Subject name: Medicine
Inactivation of coisol into coisone occurs mainly in which organ? 
Select and explain. 
A. Lungs, B. Liver, C. Adrenals, D. Kidney
D: Kidney
Answer: D: Kidney 
Explanation: Coisol is inactivated to coisone by microsomal enzyme 11b-hydroxysteroid dehydrogenase type II This enzyme is mainly in the kidney. Other organs involved in this activity are colon, salivary glands and other target tissues.