Read the excerpt from Daniel’s comparative essay.

(1) Despite the many features shared by short and long fiction, the structure of a short story is very different from that of a novel. (2) A short story follows the rule of one. (3) It's about one person, and one important thing happens. (4) In contrast, a novel has time to develop many characters and explore many events.

Which sentence best revises sentence 3 to use formal language?

It focuses on one main character and one main plot event.
That is, short stories just look at one character and one thing.
It talks about one main character and one important thing that happens.
What I mean is it centers on a main character and a single plot occurrence.

It focuses on one primary character and one significant event.