Task: Question Generation
Input (English): Background Paragraph: A comet tail—and coma—are features visible in comets when they are illuminated by the Sun and may become visible from Earth when a comet passes through the inner Solar System. As a comet approaches the inner Solar System, solar radiation causes the volatile materials within the comet to vaporize and stream out of the nucleus, carrying dust away with them. Separate tails are formed of dust and gases, becoming visible through different phenomena; the dust reflects sunlight directly and the gases glow from ionisation. Most comets are too faint to be visible without the aid of a telescope, but a few each decade become bright enough to be visible to the naked eye. 
Story: This year thee comets would be of interest, comet A, comet B, and comet C. Comet A and comet B would enter the inner solar system. But comet C would not enter the inner solar system. Moreover, comet A is categorized as a bright comet, but comet B is categorized as a faint comet.
Output (English): Which comet's tail would not be visible from earth, comet A or comet C?