The message or topic/point that you want to get across to your audience.
Answer:
C.
Since she’s publishing on a website, anyone might read her posting, so she should use a formal style.
Explanation:
yea
There are 8 of them so we need to choose the four best.
My choices are in no particular order.
4. Anytime the horizon narrows and widens, you have to take care in what you are seeing. It sounds to me like a pair of scissors or sheers that are also moving up and down. Pretty scarry.
5. Jagged with waves. Jagged!! That's pretty descriptive.
6. Pointed like rocks? 5 and 6 both suggest a knife.
8. The waves were barbarously abrupt and tall [<em>and each top froth making small boat navigation a problem.</em>] I've added the last to make it clear that the sea was ominous.