Is a ball at rest in a penalty area considered a ball in play?

A ball at rest in a penalty area is indeed considered a ball in play. This is based on the rules of golf, which stipulate that a ball remains in play unless it is explicitly ruled otherwise, such as being lost or out of bounds. A penalty area is defined to include water hazards and other designated areas, and the ball is treated as active unless specific actions are taken that would affect its status, like grounding the club or declaring it unplayable.

The other options present scenarios that deviate from the established rules. For instance, marking a ball or its position does not change its status; it remains in play unless it has been lifted or otherwise ruled out. Similarly, restrictions that apply only to particular areas of the course, like the fairway, do not apply to a ball at rest in a penalty area. Therefore, understanding the rules regarding penalty areas affirms that the ball's status while at rest is actively engaging with the ongoing play of the game.