Answer:
c. pressure and gravity.
Step-by-step explanation
The entire proc:ess of star formation involves a delicate balance between the forces of pressure and gravity. Gravity plays a crucial role in bringing together the vast amounts of gas and dust present in interstellar clouds, creating regions of high density. As the density increases, so does the gravitational attraction between particles, causing the cloud to collapse under its own gravity.
As the cloud collapses, the pressure increases due to the compression of the material. This rise in pressure counteracts the gravitational force, creating an equilibrium. However, the collapse continues as long as gravity overcomes the pressure, leading to further compression and heating of the core.
The core temperature increases as the collapse progresses, reaching a point where nuclear fusion can begin. At this stage, a protostar forms, and the balance between pressure and gravity stabilizes as the energy generated by fusion counteracts the gravitational force trying to collapse the star further.
During the subsequent evolution of the star, other factors such as heat, radiation, rotation, surface temperature, luminosity, and distance come into play, but the initial process of star formation is primarily governed by the balance between pressure and gravity.