Answer:
B.
Explanation:
This is from what i've read
It can't be D because it's just saying something where a student would use a phone, which isn't the most important thing
It isn't C because from what you've shown, it states nothing about that it should be used for emergencies only
And it isn't A because it just states what there used for, and it's not that descriptive
It's B because it states the most important part of the text.
