A person lives in a hilly area.The drinking water and food grown in this area are poor in a mineral P. The deficiency of Pin the body causes an abnormal enlargement of the gland Q leading to a disease R. The disease R, however,does not occur in the people living in coastal areas.
A) What is the name of mineral P?
B) Name the gland Q.
C)What is the disease R?
D)Why does the disease R not occur in coastal areas?