When does a player become a kicker?

A player becomes a kicker when they legally kick the ball. This is significant because the designation of "kicker" is linked to the action that defines their role on the field. Prior to the kick, a player may be in position or even receive a snap, but these actions alone do not confer the title of kicker. It is the act of executing a legal kick that establishes the player in this specific capacity during a play.

The other choices do not accurately reflect the definition of a kicker in a football context. Simply taking a position or getting set for a play does not necessarily involve the player performing their primary function as a kicker, which is to kick the ball. Thus, the only moment when the title of kicker applies is during the action of kicking.