Final answer:
Phosphorescence is the correct answer. It refers to the emission of light from a material even after the excitation source is removed.
Step-by-step explanation:
When a screen emits light after an exposure is terminated, it is exhibiting phosphorescence. Phosphorescence is a natural phenomenon where certain compounds absorb light of a specific energy and subsequently emit light that is lower in energy (larger wavelength) than the light absorbed. This emission of light continues even after the excitation source is removed, unlike fluorescence which ceases immediately after the excitation source is turned off.