Answer: A. Graves' disease
Explanation: Hyperthyroidism is caused by an overactive thyroid. The thyroid gland produces too much thyroxine. This results in an overall increased metabolism.
There are several conditions that can cause the thyroid to become overactive:
* Graves’ disease is an autoimmune disease
that may have a genetic predisposition. It’s
more common in women.
* Toxic adenoma
* Plummer’s disease is characterized by
goiter, an enlarged thyroid.
* Thyroiditis (inflammation of the thyroid)...PF