Question

carrots contain high amounts of vitamin a and are good for general eye health. however, carrots will not improve night vision. that myth goes back to british propaganda during world war ii. in 1940, the german luftwaffe, or air force, began bombing britain at night. in response, the british government ordered people to turn off their lights; the government wanted to make it difficult for german pilots to hit their targets. a new technology, radar, allowed the british air force to track and shoot down the german planes without light. to keep the technology secret, the government told the media that their pilots could see the german planes because they consumed so many carrots. consequently, people began to believe that eating carrots would help them see better in the dark.
what is the main, or central, idea of the passage?
because of a british media campaign, people thought that eating carrots would improve their night vision.
during world war ii, the british government told the media that their pilots ate a lot of carrots.

Explanation:

The passage first clarifies carrots support general eye health but do not improve night vision, then traces the origin of that myth to British WWII propaganda: the government spread the story that pilots ate carrots to see at night to hide their radar technology, leading people to believe the false claim. The first option captures this full central idea, while the second only states a single detail from the passage.

Answer:

Because of a British media campaign, people thought that eating carrots would improve their night vision.