The used rhetorical device is Hyperbole.
Saying that something is a billion times better is hyperbole because it is not really that much better, you would just be over exaggerating.
Answer:
Out of these, I would say the answer is terse.
Explanation: while the others are also short, this one stops rather abruptly almost as if you want to answer. Hope this helps! :)
Answer: 1# their post can get few likes causing them to have anxiety
2# people can say negative things about their post, causing depression
Explanation: these are just examples
D The exits and entrances are similar to the acting on a stage
