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)
all lamps from the rooms with king-sized beds
all lamps in booked rooms
400 lamps on the first 10 floors
100 lamps on each floor chosen randomly

100 lamps on each floor chosen randomly