When told to "Standby" after requesting closed, when should aircrew turn crosswind?

The correct choice is to turn crosswind no later than 2 miles past the departure end of the runway to ensure safe and effective traffic flow. This guideline helps maintain a safe distance from the runway and facilitates separation from other aircraft. By waiting until reaching 2 miles past the departure end, aircrew can ensure that they have sufficient altitude and distance from the runway environment, reducing the risk of interfering with any other aircraft that may be departing or landing.

Turning crosswind too early, such as immediately upon receiving "standby" or at the departure end, could compromise safety by potentially conflicting with the operations of other aircraft. Additionally, turning at 1 mile past the entry point may not provide enough separation depending on the specific airport and traffic conditions. Thus, the recommendation to turn no later than 2 miles past the departure end balances the need for traffic management with the safety of flight operations.