Astronomy — Identifying the Inner (Terrestrial) Planets Which set correctly names the inner planets of our Solar System, located between the Sun and the asteroid belt?

Introduction / Context:
The Solar System is divided into inner (terrestrial) planets and outer (giant) planets. Knowing which are which helps interpret differences in composition, density, atmosphere, and the presence of rings or many moons. Terrestrial planets are rocky and metal-rich; giants are gas/ice-rich and much larger.

Given Data / Assumptions:

• Inner planets lie inside the main asteroid belt.
• They are rocky bodies with solid surfaces.
• We must pick the correct quartet.

Concept / Approach:
From the Sun outward: Mercury, Venus, Earth, Mars are the inner planets. Beyond the asteroid belt lie the outer planets: Jupiter and Saturn (gas giants), Uranus and Neptune (ice giants). Older lists sometimes included Pluto as a ninth planet; it is now a dwarf planet in the Kuiper Belt and was never an inner planet.

Step-by-Step Solution:

Verification / Alternative check:
Any elementary astronomy chart shows the four terrestrial planets inside the asteroid belt, confirming the selection.

Why Other Options Are Wrong:

• Options A/B/C list outer planets and/or Pluto, which are not inner planets.

Common Pitfalls:
Assuming “inner” means “smaller” without considering orbital position. While inner planets are smaller, the defining criterion is their location inside the asteroid belt.

Final Answer:
Mercury, Venus, Earth, Mars