What patterns are there in prime numbers

That they are only divisible by 1 and themselves.
2 divisible by 2 and 1
3 divisible by 3 and 1
5 divisible by 5 and 1

And so on...

Well, prime numbers cannot be divided by any numbers other than 1 and that number.
Some prime numbers are 7, 11, 13, 17, 19, 23, and more.

Composite numbers on the other hand are numbers like 4... They can be divided by 1, their number and other numbers, but in this question you do not need to know that.
Hope this helps. 

I'm pretty sure it's b). i try drawing the functions out and b is the one that stands out or isnt a "line"