Question

in a model of the solar - systems formation, which of the following represents the process that formed the sun?
a massive star explosion provides material.
the solar nebula collapsing and forming a dense core.
planetesimals colliding and sticking together.
comets merging to create the central star.

Explanation:

The widely - accepted theory for the Sun's formation is the collapse of the solar nebula to form a dense core. A massive star explosion (supernova) provides heavy elements but not the main process for Sun - formation. Planetesimals collide to form planets, not the Sun. Comets merging is not the process for Sun - formation.

Answer:

The solar nebula collapsing and forming a dense core.