Correct Answer: a moon
the correct answer to the question "which of the following bodies revolves around a planet?" is a moon. moons, also commonly referred to as natural satellites, are celestial bodies that orbit planets. this relationship is a result of gravitational forces whereby a moon is caught in the gravitational field of the planet, leading it to continuously revolve around the planet.
in contrast, other options such as comets, stars, and asteroids do not fit the description of bodies that revolve around a planet under normal circumstances. comets are small celestial bodies composed mainly of volatile ices mixed with dust. they typically have highly elliptical orbits that bring them close to the sun and then out into the farther reaches of the solar system, but they do not orbit around planets. they are primarily influenced by the sun's gravity.
stars, including our sun, are massive luminous spheres of plasma held together by their own gravity. stars are the central bodies in solar systems, around which planets revolve, not the other way around. thus, a star cannot be considered as a body that revolves around a planet.
asteroids are small rocky bodies that mostly reside in the asteroid belt between mars and jupiter, although they can be found throughout the solar system. like comets, their orbits are primarily influenced by the sun, not by individual planets. while some planets, like earth, have near-earth asteroids that pass close by, these asteroids do not revolve around the planets.
therefore, among the given options, only a moon is the correct answer as it is the only body that characteristically revolves around a planet, making part (d) the accurate choice.
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