The correct answer is B.) gravitational forces brought together several moon-sized bodies called planetesimals to form larger bodies that became planets.
During the formation of the solar system, dust and gas in the protoplanetary disk around the early sun began to coalesce due to gravitational attraction. These small particles and ice-clad objects combined over time to form larger bodies, known as planetesimals. The gravitational forces between these planetesimals led them to collide and merge, eventually forming the planets we see today.