Question

read the passage.
snake venom and blood pressure
british scientist sir john vane was studying hypertension, or high blood pressure, a serious condition that increases the risk of death from heart disease and other problems. he was intrigued by the venom of the bothrops jararaca pit viper. this snakes bite produces a dramatic drop in blood pressure, causing victims to collapse suddenly. vane reasoned that if scientists could learn how pit viper venom lowers blood pressure, they might be able to create a medicine that uses a similar mechanism. in the 1970s, vane and his colleagues conducted many experiments with the venom to try to isolate the components that affect blood pressure. they discovered that the venom blocks the production of angiotensin, a hormone in the human body that constricts blood vessels and consequently raises blood pressure. as vane had predicted, these findings led to the development of a new group of medications, ace inhibitors. these medicines are now widely used to treat hypertension.
what is the main, or central, idea of the passage?
medication derived from pit viper venom works to lower high blood pressure.
venom in the bite of a pit viper causes peoples blood pressures to drop suddenly.
pit viper venom blocks the production of a hormone involved in the regulation of blood pressure.

Explanation:

The passage focuses on how Sir John Vane studied pit viper venom, discovered its mechanism (blocking angiotensin production), and this led to developing ACE inhibitors (medication) to treat hypertension. The first option captures the central idea of the medication derived from the venom treating high blood pressure. The second option is just about the venom's effect on blood pressure, not the main idea of developing medication. The third option is about the mechanism, but the main idea is the development of medication from the venom for hypertension.

Answer:

Medication derived from pit viper venom works to lower high blood pressure.