There are many reasons why Zachary can't concentrate. He might have something on his mind that is bothering him, he could be hungry, he could not have a lot of energy. The best thing Zachary could do to help the paper not suffer is leave his desk and paper alone for about a half an hour, and maybe eat something, or just take a break. Maybe take a nap to get some energy back up so that he can get everything he needs in his paper.
Usually the media is trying to get you to buy or do something it can be either a positive or negative way of getting you to buy that product.
Most likely c. because heredity is genetics or ancestry
They would advise to not eat hearty foods and go for walks and stuff, this is right trust me it happened to my mom