To comply with atc instructions for altitude changes of more than 1,000 feet, what rate of climb or descent should be used?
a) as rapidly as practicable to 1,000 feet above/below the assigned altitude, and then between 500 and 1,500 feet per minute until reaching the assigned altitude. b) as rapidly as practicable to 500 feet above/below the assigned altitude, and then at 500 feet per minute until the assigned altitude is reached. c) 1,000 feet per minute during climb and 500 feet per minute during descents until reaching the assigned altitude.