Parts of the following sentence have been given as options. Select the option that contains an error.
There are eight planets in our solar system and a Earth is the third planet from the Sun.

Correct option is C

Explanation:
• “a Earth” is incorrect because “Earth” is a proper noun and starts with a vowel sound.
• It should be: "the Earth", not "a Earth".
Correct: …and the Earth is the third planet…
Grammar Rule:
Use “the” before unique nouns (like the Sun, the Earth, the Moon).