What condition must be met when ferrying a large turbine-engine-powered airplane with an inoperative engine?

When ferrying a large turbine-engine-powered airplane with an inoperative engine, the requirement that weather conditions must be VFR (Visual Flight Rules) at both takeoff and destination is crucial for safety. This ensures that the flight can be conducted with visual reference to the ground, which is especially important for managing the aircraft's limited performance without full engine power. VFR conditions allow the flight crew to navigate and avoid obstacles or adverse weather, which is vital under the compromised performance of having a non-operational engine.

The other options do not address the critical factors necessary for safely conducting a flight with an inoperative engine. While flying only during certain times or restrictions on passenger seating may be relevant to overall operational procedures, they do not directly address the increased risk associated with engine failure and the need for adequate weather conditions that allow for safe visual navigation and landing. Therefore, maintaining VFR conditions at the departure and arrival points significantly enhances safety during such a compromised operation.