All of the following statements apply to the reinforcing stimulus type sunlight lamps EXCEPT

• A. Radiation below 2800 A is absorbed by the Corex D glass envelope
• B. Radiation includes both ultraviolet and infrared
• C. Produces ultraviolet effectiveness at 24 weeks
• D. Requires no special electrical fixture

Answer: (C)

Sunlight lamps used as reinforcing stimuli deliver a defined spectrum and have safety features that shape how they work. The glass envelope called Corex D blocks the most energetic ultraviolet radiation, so wavelengths shorter than about 280 nanometers (2800 Å) are absorbed and don’t reach the user. The lamp’s spectrum includes both ultraviolet and infrared components, matching its daylight-mimicking purpose. It’s designed to be used with standard electrical fixtures, so no specialized wiring is required in setups that use these units. The key point is that ultraviolet output is available as soon as the lamp is powered; there isn’t a delayed “ultraviolet effectiveness” that only appears after a fixed period like 24 weeks.