True or False: You can instruct an aircraft to squawk a new code before it enters your area of responsibility.

In radar operations, air traffic controllers are typically tasked with managing the flow of air traffic within their specific area of responsibility. It is a standard procedure for controllers to issue a new transponder code to an aircraft that is already within their controlled airspace, as this allows for accurate identification and tracking of the aircraft on radar.

Instructing an aircraft to squawk a new code before it enters the controller's area would not be standard practice, because the aircraft is not yet under the controller's airspace jurisdiction. Ensuring proper sequencing of instructions and responsibilities is critical for the safety of all aircraft in flight. Therefore, until an aircraft officially enters an area of responsibility and new instructions can be given, the controller must rely on existing codes and communications managed by the previous authority.

The other options suggest scenarios that either misrepresent when instructions can be provided or create confusion regarding aircraft classifications and emergency situations. Thus, the assertion that you cannot instruct an aircraft to squawk a new code before it enters your area of responsibility is accurate.