Correct item: the coach’s bias toward the football team.
The coach says, "I know the football players aren’t to blame because they are well-disciplined kids.” That's his impression of the football players from his work with them as a sports team. But does he know, factually, that they are disciplined in their approach to the classroom and to arriving on time for class? The fact that the football coach naturally is inclined to speak in defense of his players doesn't mean his views should be rejected simply because of her position as coach. If his views are supported by solid arguments and evidence in favor of what he asserts, then his views should be considered on their merits. But without providing further evidence from actual classroom conduct, his views could be the product of personal bias.
When evaluating sources, always examine whether the person seeks to provide objective information, as opposed to advocating a bias for or against a particular position or groups.
