Final answer:
In a laser scanning confocal microscope, short-wavelength incident light is absorbed by the specimen and then reemitted at a longer wavelength. This occurs because the emitted light has less energy than the absorbed light, which indicates an increase in wavelength. The correct answer is B) short, longer.
Step-by-step explanation:
In a laser scanning confocal microscope, short-wavelength incident light is absorbed by the specimen and reemitted at a longer wavelength. This is because when a material absorbs photons of light, it often re-emits them at a lower energy level, resulting in a longer wavelength of light being emitted than was originally absorbed.
The energy of a photon is inversely proportional to its wavelength; therefore, light with a shorter wavelength has higher energy and light with a longer wavelength has lower energy. Following the question's framework, the correct answer is B) short, longer.
To elaborate, the electromagnetic spectrum shows that short wavelength light, like ultraviolet light, has a higher frequency and energy. When this light is absorbed and then re-emitted, the re-emitted light has less energy, thus a longer wavelength.
For instance, if a specimen is illuminated with ultraviolet light, which has a shorter wavelength, it will typically re-emit light in the visible spectrum, with a longer wavelength than the ultraviolet light. This phenomenon is part of the basis for fluorescence microscopy, which is integral to how confocal microscopes operate.