What constitutes a major foul leading to a direct free kick?

A direct free kick is awarded for specific infractions that are considered major fouls. Tripping or kicking an opponent falls under this category because these actions can significantly disrupt the opponent's ability to play the ball and can lead to injury. The Laws of the Game recognize that these types of fouls not only impact the flow of the game but also affect the safety of the players. By awarding a direct free kick, the referee is acknowledging the serious nature of the foul and providing the opposing team a chance to score.

The other choices do not meet the criteria for a major foul that warrants a direct free kick. Minor contact that has no effect does not disrupt the play significantly enough to be considered a foul. Violent conduct is indeed a serious offense, but it is only one subset of fouls that lead to direct free kicks, and it must be assessed in the context of how it impacts the game. Lastly, taking no action is contrary to the role of a referee, who must enforce the rules and ensure the safety of all players on the field.