Final answer:
A. is fluorescent.. A paint pigment that absorbs blue light and emits red light is fluorescent, as demonstrated by fluorescent dyes like TEXAS Red that emit red when excited by blue light.
Step-by-step explanation:
A paint pigment that absorbs blue light and emits red light would be described as fluorescent. Fluorescence is a process where a substance absorbs light at one wavelength and then emits light at a longer wavelength. An example is the fluorescent dye TEXAS Red which can be excited by blue light to emit red light. This is because the absorbed energy causes electrons to jump to higher energy states and when they fall back to their ground state, they emit photons at a lower energy level, which corresponds to a longer wavelength - in the visible spectrum, this means a shift towards red.
On the other hand, phosphorescence is related but distinct as it involves a delayed emission of light after the initial absorption. While fluorescent materials emit light almost instantaneously, phosphorescent materials 'glow in the dark' by emitting light for an extended period after being energized.
Therefore, the correct answer to the question is that a paint pigment that absorbs blue light and emits red light is (C) fluorescent or phosphorescent. It's important to note that the use of such pigments is not restricted to lasers, and they certainly do exist, as seen in various applications including microscopy and dyes.