3. What are the drawbacks to natural light? a. It can create a substantial heat gain within a building. D. It is considered an inefficient light source. C. It has poor color rendition. d. All of the above. 4. David, the maintenance manager at the Riaston Hotel, purchased some replacement lamps for the hotel's guestrooms. The lamps have a lamp life of 1,000 hours; this means that each lamp is: a. guaranteed to last for 1,000 hours before burning out. D. expected to last for approximately 1,000 hours before burning out. C. guaranteed to last for 500 hours before burning out. expected to last for approximately 2,000 hours before burning out