Answer by choosing the correct options
 
 ​Mary and Manoj were classmates and good friends. On turning 11, Mary developed a little bulge on the front of her neck. She visited the doctor who gave her medication and advised her to take iodine-rich food. Similarly, a bump was developed on the front of Manoj’s neck when he turned 12. However, the doctor told him that it was a normal part of growing up.
 
i. Why did the doctor advise Mary to take iodine-rich food?
 
ii. What is the bump on Manoj’s neck called, and why did it appear during adolescence?
 
iii. ​What do the conditions of Mary and Manoj together show about the changes that occur during adolescence?