阅读下面材料, 从每题所给的A、B、C、D四个选项中选出最佳选项。
While the mobile Internet is changing the way we live, more and more old people in China are getting in on the digital world, although they will have some trouble.
Yang Su, a 61-year-old professional micro vlogger (微视频博主), is among them. He is both a pianist of Shenzhen Symphony Orchestra (交响乐团). With more than 2. 3 million followers on China's famous short video app "Douyin", his videos have been watched by over 1 million times.
"Three years ago, my son put a short video of me playing the piano at home on ‘douyin', and hours later it was played over 1 million times," Yang remembered.
However, it's not easy for him to learn how to film a video. He needs to play through the music since he doesn't know how to edit (编辑) and cut clips. His child helps him a lot later. "The Internet has opened the door to a new world," Yang said. "I always keep myself busy and feel very young at my age. "
Do other old people get used to the digital world like Yang? Ding Qiulin is a 73-year-old man from Hunan. "I got my smartphone more than one year ago but I only use WeChat for video calls," he said. Ding finds it hard to learn to use other apps.
____________▲_____________ Luo Xu, a post-90s volunteer, joined a non-profit （非盈利）organization in Beijing nine years ago to teach old people how to use the Internet. "While I am helping people aged between 50 and 90 years old, I have a strong feeling of pleasure," Luo said.
