Which of the options below is a good description of what is taking place in the Orion Nebula?

A. Gravity is pulling gas and dust in the darkest regions of the nebula that will someday become new stars.

B. Gravity is pushing gas and dust into space in the expansion of the universe, supporting the idea that our universe is expanding.

C. The stars that once provided light and energy are dying as they use up their original sources of energy from nuclear fusion.