Iodine is associated with which of the following hormones?

On an educational trip to Uttaranchal,Ketki and her friends observe that many local people have swollen necks. Please help Ketki and her friends to find out the solutions to the following questions.
$(a)$ Which probable disease are these people suffering from?
$(b)$ How is it caused?
$(c)$ What effect does this condition have on pregnancy?

$A$ person appears fat,short,and stocky and has a stupid look and protruding tongue due to the hormonal deficiency of:

Match the given endocrine gland with its hormones,functions,and deficiency symptoms accurately.

Which of the following disorders is related to the thyroid gland?

If the thyroid gland is completely removed from a tadpole,it will