Which sentence could be added to the end of the introduction to strengthen it? A. Throughout the world, Internet use has increased dramatically. B. Teenagers are also one of the top consumers of new products. C. However, these teenagers do not always use the Internet wisely. D. In effect, the lack of communication skills affects relationships.

Aman lives on the twelfth floor of an apartment building. every morning he takes the elevator down to the lobby and leaves the building. in the evening, he gets into the elevator, and, if there is someone else in the elevator -- or if it was raining that day -- he goes back to his floor directly. otherwise, he goes to the tenth floor and walks up two flights of stairs to his apartment.