Question

Consider the following situation and explain what might be a problem with the credibility of the source or the thinking involved: You got your essay back in English class and you received a "B" on it. The girl sitting behind you, a friend of yours, also received a "B" and her boyfriend, who is another period class with the same teacher and the same subject, also received a "B." You concluded then that no one that wrote that particular assignment for that particular teacher received an "A." Pitfalls in credibility?

help please!!!??!