The correct answer is C) well-conducted drills. The key to rescuing a man overboard is thorough, well-executed crew drills. Regular practice with the crew on man overboard procedures, including proper notification, maneuvering the vessel, retrieving the person, and administering first aid, is critical to an effective and timely rescue. Well-conducted drills ensure the crew is prepared to respond quickly and efficiently, which is the most important factor in a successful man overboard recovery. The other options, while important, are secondary to the crew's training and readiness through regular drills.