The word they” in paragraph 2 refers to .

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.

Walk down any streets in the world and you will see young people holding smartphones to their ears, sending text messages or logging on to Facebook. Companies around the world are reacting to the daily habits of young people and sending their ads where their customers are online.

Levi Strauss, the American jeans maker, discovered a new way to reach its Asian customers through advertising. He chose 20-year-old teenagers being from Singapore, Hong Kong, Korea, and India to spread the world about his clothes. One of those ad carriers is a girl called Bright, a writer and blogger from India. She talks about the clothes on the internet and answer questions from her friends. According to Bright, they want to know more about the products and trust her judgement more than a commercial on television. She gets free clothes in exchange for writing one post a day.
Social media advertising has been adopted by other US-based firms too. Procter and Gamble launched an online ad campaign. The company invites consumers to ask questions about a product. Answers are then broadcast on YouTube.
Although internet advertising is catching on very fast, companies still must be careful with these new methods.

(Adapted from english-online.at)