In a flight plan when the destination aerodrome is A and the alternate aerodrome is B, the final reserve fuel for a turbojet engine aeroplane corresponds to:
15 minutes holding 2,000 feet above aerodrome A
30 minutes holding 2,000 feet above aerodrome B
30 minutes holding 1,500 feet above aerodrome B
30 minutes holding 1,500 feet above aerodrome A