Earth originated from material in which environment?

• A. The Kuiper Belt.
• B. The Oort Cloud.
• C. Interstellar medium far from stars.
• D. The solar nebula.

Answer: (D)

Earth formed from the gas and dust in the solar nebula—the rotating disk surrounding the young Sun. In this disk, tiny dust grains stuck together to form rocks and metals, grew into planetesimals, then protoplanets, and eventually the terrestrial planets like Earth. The Kuiper Belt and Oort Cloud are distant remnants of the outer solar system, not the birthplace environment of Earth. The interstellar medium far from stars is the diffuse material between stars, not the dense, organized disk around a newborn star. So the solar nebula is the environment that provided Earth's original material and setup for planet formation.