What must players do at the start of a soccer match?

At the start of a soccer match, players must take their positions on the field and await the referee's whistle. This emphasizes the importance of order and readiness as the match is initiated. Positioning ensures that players are properly stationed according to their roles and responsibilities on the field, allowing for a smooth start to the game. The referee’s whistle serves as the official signal to commence play, indicating that all players should be prepared and alert to begin the match.

The other options, while may be relevant activities in the context of soccer, do not specifically pertain to the immediate actions required at the kickoff. For instance, shaking hands is typically done before the match starts but is not a requirement at the exact moment of kickoff. Warming up and practicing set plays, though essential for preparation, occur before the match rather than at the start. Engaging in a team huddle for motivation can be beneficial for team spirit and strategy but does not directly relate to the official start of the match. Thus, awaiting the referee’s whistle after taking proper positions is the correct and necessary procedure as the game begins.