Final answer:
The Arecibo Telescope, known for discovering the first extrasolar planets, is located in Puerto Rico. It was the world's largest radio telescope before its collapse in 2020. correct option is C
Step-by-step explanation:
The Arecibo Telescope, which discovered the first extrasolar planets, is located on the West Indies island of Puerto Rico. This massive radio telescope was built in a 305-meter diameter natural bowl and was once the world's largest curved focusing dish. Its construction in Puerto Rico, a location outside of the continental United States, helped cement the island's place in astronomical history despite being more known for its scenic beauty than scientific endeavors. Sadly, in November 2020, the Arecibo Observatory collapsed, which marked the end of an era for the iconic facility.