Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 29 to 33.

Social media is everywhere. You can't walk down the street without seeing people on their phones, posting pictures of themselves or updating their 'status'. It's not just young people who are doing this now; adults and even grandparents are using social media too. But is it a good thing? Here are some of the pros and cons of social media.

One of the biggest advantages of social media is that you can communicate with your friends and family instantly, wherever they are in the world. You can also make new friends with people who have the same interests as you. Another advantage is that you can share photos and videos easily. For example, if you go on holiday, you can post your photos on Instagram so all your friends can see them.

On the other hand, one of the disadvantages of social media is that it can be addictive. Some people spend hours every day on Facebook or X (Twitter), and this can affect their real-life relationships. Another problem is that sometimes people use social media to say nasty things about others or to invade their privacy. For example, celebrities often complain that the paparazzi follow them and take photos of them when they don't want to be photographed.

There are many different types of social media, but some are more popular than others. Facebook is still the most popular social media site in the world, with over 2 billion monthly active users. YouTube is also very popular, particularly with young people, and it has made many ordinary people famous, for example, Justin Bieber. Recently, there has been a lot of discussion about whether social media sites like Facebook should allow fake news. Some people think that fake news stories on social media influenced the last US election, and that these stories need to be censored. Others believe that this would be against the right to free speech.

In conclusion, social media has changed our lives in many ways, and it continues to gain popularity. However, we need to be careful how we use it, and not let it take over our lives.

What does the word "they" in paragraph 3 refer to? A. things B. celebrities C. paparazzi D. relationships