- Mars is a kind of planet
- Phobos orbits mars
- Hence, phobos orbits the planet mars

- Phobos orbits the planet mars
- Moons orbit planets
- Hence, phobos is a kind of moon

Therefore, phobos is a kind of moon
Q: Phobos is one of two large objects that orbit the planet Mars. Because Phobos orbits Mars, Phobos should be classified as which type of body?
Context:
- Mars is a kind of planet 
- Moons orbit planets 
- Phobos orbits mars