Answer:
B. a non-fiction book found using the library database.
Step-by-step explanation:
A. a famous historical fiction film based on the life of William Wallace. It is not A because fiction is not real, and we need real information.
C. a gossip site that addresses William Wallace. We don't need any casual or unconstrained conversation or reports about other people, typically involving details that are not confirmed as being true. We need real information.
D. a blog written by a teenage history buff. It is not D because in a blog there can be any person writting it. Meaning people that have enough knowledge or people that don't know a lot, but we tend to find information that is trusted.
So, your correct answer is B. a non-fiction book found using the library database.