The Answer to this Question is:
D. Regardless of size, a business must be local to benefit.
It doesnt matter the size to any business to have a social media marketing, or advertising accounts.
In my town there is a local restaurant they are very small, and a family owned place, and they have there own account and because of that they get more customers every single day!
And theres the big businesses like, McDonalds, that benefit from using social media sites too!