Question

which object(s) formed last in our solar system?
the sun
the solar nebula
the inner planets
the planetesimals

Explanation:

The solar nebula was the first - a cloud of gas and dust. Then the Sun formed from the densest part of the nebula. Planetesimals are small bodies that aggregated to form planets. The inner planets formed later as the planetesimals collided and merged.

Answer:

C. the inner planets