Final answer:
The In-Flight Entertainment (IFE) system usually starts after takeoff, once the aircraft has reached a safe altitude and the crew indicates it is permissible to use electronic devices.
Step-by-step explanation:
When querying when the Flight Attendant (FL) starts the In-Flight Entertainment (IFE), it is important to note that procedures can vary by airline. However, generally, the IFE system is made available for use soon after the aircraft has reached cruising altitude or sometimes immediately after takeoff when the crew announces it is safe to use electronic devices. Therefore, the closest option to when the FL starts IFE would likely be Option 2: After takeoff, provided there are no restrictions by the airline or unique circumstances delaying its availability.