Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions from 36 to 42.

When I was a teenager playing Ubisoft's Assassin's Creed series, I definitely wasn't looking to learn things. But with 11 main AC games all set during different times and places in history - like ancient Egypt, Greece, and America during the Revolutionary War - I was bound to learn something, even if just by accident. And I definitely did. One day, my history teacher passed out blank maps of the Caribbean. It was a quiz I had forgotten about. We had to label countries and major cities. Luckily, I'd been playing a lot of Assassin's Creed: Black Flag, set in the Caribbean during the golden age of piracy in the early 18th century. So I was able to draw on my life as a pirate to fill in the map, and I got an A. When I was seven, I learned to multiply quickly through a purely educational game called Treasure Mountain!, which had me solving math problems to progress up a mountain and collect treasure in a never-ending loop. And then, of course, there was Assassin's Creed. Ubisoft leaned into AC's educational potential, with very cool results. They did a lot of research to recreate Ancient Egypt in AC: Origins and Ancient Greece in AC: Odyssey, and they released an educational discovery tour for each game that lets you look around the environment with no violence, enemies, or time constraints. You can learn about the Olympic Games, and how Sparta trained its soldiers in ancient Greece, with real historical figures acting as your tour guides. Or jump over to ancient Egypt to check out mummies and climb on the pyramids. Obviously, Assassin's Creed can't teach you everything you need to know about the ancient world - but the games do make that world come alive for people who are reluctant to learn, like I was. If you're looking for some other options, Minecraft is incredibly popular with kids of any age. Minecraft: Education Edition is free for everybody with a student email until at least June 30, and features over 500 pre-made lesson plans for things like coding, history, English, and much more. For example, there is a lesson plan on how to write clear instructions for in-game actions, and another that lets kids learn about slopes by building a roller coaster. (Source: https://www.npr.org/)

The word “they” in paragraph 2 refers to _______. A. expeditions B. decades C. species D. scientists