Which of the following is not a requirement for a throw-in?

For a throw-in, certain fundamental requirements must be met to ensure it is performed correctly according to the Laws of the Game. The requirement that specifies that the player must deliver the ball from behind the head is crucial. This action ensures that the throw-in is executed in a manner that allows for a fair and consistent restart of play.

When executing a throw-in, the player must face the field of play to clearly indicate their intent to resume the game. Additionally, it is specified that part of each foot must remain on or touching the touchline, ensuring that the throw-in is taken from the correct spot. While players often use both hands to throw the ball, there is no explicit requirement stating that a throw must only be executed with one hand. Therefore, the correct choice is that throwing with one hand is not a requirement for a throw-in. In fact, using both hands is commonly practiced to effectively deliver the ball into play.