What is the correct position for players at the head-end of the rink?

The correct position for players at the head-end of the rink is to stand behind the jack if their team is in control of the head. This is a standard practice in bowls to ensure that players have a clear view of the head and can effectively assess the situation after the delivery of bowls. Standing behind the jack allows players to observe how the bowls are positioned relative to the jack and makes it easier to strategize their next move.

When a player is in this position—behind the jack—they can also avoid interfering with the play and maintain a proper level of etiquette within the game. The positioning around the jack is critical for communication between team members, allowing discussions on tactics and bowl placements.

Other options either do not adhere to the conventional play etiquette or do not prioritize clarity and visibility during the game. Furthermore, positioning anywhere on the green, regardless of team control, would likely lead to confusion and potential interference with ongoing play. Thus, the specified position behind the jack is the most appropriate and strategic choice for players at the head-end.