Answer:
A
Explanation:
A is a formal answer that does not make fun of people who do not think the same as the author. For example, B calls them "Silly" C asks sarcastically how they can complain, and D writes that it's Ironic people use computers to condemn NASA. All of these answers are informal because they poke fun at the audience that does not agree with their point instead of stating their argument clearly, like A.
