Both because it depends on the message
Explanation:
We can help to advertise an event through the social media. Social media is a very good equipment which can help in the advertisement of event. or public awareness can also help in the advertisement of an event.
It helps bring the reader into what you are going to talk about it's like a tour guide and you slowly showing them what it's about but you also want to interest them so they read on and get to the central /main idea
C. understand the meaning of the paper