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: Medicine
Which of the following is associated with hypothyroidism Is sub Himalayan region? 
Select and explain. 
A. Cu, B. Fe, C. Zinc, D. Selenium
D: Selenium
Answer: D: Selenium 
Explanation: Answer is option 4 Selenium Hypothyroidism in Himalayan region is associated with iodine deficiency and selenium deficiency. Selenium forms pa of seleno-enzyme responsible for conveing T4 to T 3 . In Himalayan areas alps andes flooded river areas are deficient with iodine and it is fuher worsened by selenium deficiency.