Answer: D.A local newspaper reported that several players admitted they'd had a big argument before the game and had felt the effects of the argument on the field.
Option D is the most reliable source, as it tells us what the players thought. Not only were they responsible for the outcome, but they have admitted that the team was impacted by an argument before the game.
Option A is hearsay, and it comes from a person who was not directly involved in the game. Option B and Option C, on the other hand, give reasons for the loss (coaching and weather) that do not support the argument.