Which of the following is a common reason for issuing a yellow card?

Issuing a yellow card is a common disciplinary measure used by referees to address various offenses during a match. Tripping an opponent is considered a serious infringement as it directly impacts the safety and fairness of the game. This type of foul typically disrupts the flow of play and can lead to dangerous situations, especially if done recklessly or without regard for the opponent's safety. Therefore, referees use a yellow card to signal that the action warrants a caution, indicating to the player that such conduct is unacceptable and could lead to more severe penalties if it continues.

Other options, while similar in the sense that they can lead to cautions, may not carry the same immediate impact on the opponent's play. Excessive celebration, for example, is generally considered less critical to the direct conduct of the game itself. Foul language usually indicates unsportsmanlike behavior but may not always warrant a yellow card depending on the context. Changing shirts is typically not a rule violation that would necessitate a caution unless it disrupts the game. Thus, tripping an opponent stands out as a clear and actionable reason for a yellow card due to its direct involvement in gameplay and player safety.