Earth,Mars and Mercury are a rocky plants. Uranus is a ice giant. So the answer is option c

Odd One Out: Uranus

Explanation:
Uranus is the odd one out among the given options (Earth, Uranus, Mars, and Mercury) because it has several unique characteristics that differentiate it from the other three planets.

1. Size and Composition:
- Uranus is the seventh planet from the Sun and is the third largest planet in our solar system.
- Unlike Earth, Mars, and Mercury, which are terrestrial planets with solid surfaces, Uranus is a gas giant composed primarily of hydrogen and helium.

2. Atmosphere:
- Uranus has a thick atmosphere made up of hydrogen, helium, and methane.
- The presence of methane in its atmosphere gives Uranus a bluish-green color, while the other three planets have different colorations due to their atmospheres and surface compositions.

3. Tilted Axis:
- One of the most distinctive features of Uranus is its extreme axial tilt. While Earth, Mars, and Mercury have relatively small axial tilts, Uranus is tilted on its side, with its axis almost parallel to the plane of its orbit around the Sun.
- This unique tilt results in extreme seasons on Uranus, with each pole experiencing 42 years of continuous daylight followed by 42 years of darkness.

4. Rings:
- Uranus is also known for its system of rings, which is not present in Earth, Mars, or Mercury.
- The rings of Uranus are composed of dark particles and are much less prominent and visible compared to the well-known rings of Saturn.

In conclusion, Uranus is the odd one out among Earth, Uranus, Mars, and Mercury due to its gas giant composition, distinct bluish-green coloration, extreme axial tilt, and the presence of rings.