A hotel maintenance crew wants to estimate how many of the 12,000 lamps in their 30-story hotel need a new light bulb. Which of the following is a random sample of lamps to be inspected? (1 point)
• 400 lamps on the first 10 floors
• all lamps from the rooms with king-sized beds
• 100 lamps on each floor chosen randomly
• all lamps in booked rooms