This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
DIAGNOdent, a diagnostic device for assessing the presence or absence of pit and fissure caries. It is a: 
Select and explain. 
A. Fiberoptic transilluminator, B. Portable digital X-ray device, C. Laser fluorescence device, D. Electronic explorer
C: Laser fluorescence device
Answer: C: Laser fluorescence device 
Explanation: INFRARED LASER FLUORESCENCE (DIAGNOdent)

DIAGNOdent is an instrument designed to facilitate the detection and quantification of dental caries on occlusal and smooth surfaces. 
It uses a diode laser light source and a fiberoptic cable that transmits the light to a handheld probe with a fiberoptic eye in the tip. 
The light is absorbed and induces infrared fluorescence by organic and inorganic material. 
The emitted fluorescence is collected at the probe tip, transmitted through ascending fibers, and processed and presented on a display window as an integer between 0 and 99.