Darwin's book suggested that organisms evolve through natural selection.
Answer:
C. The universe coalesced into one solar system after the Big Bang.
Explanation:
This is true because, since she is writing about Big Bang theory, she would have to include how the universe was able to expand to one solar system made up of different planetary bodies. This explanation would help someone reading her writeup to understand what the Big Bang theory is all about.
Every person has their own part to play or if you want to get scientific then a niche. And if somebody doesn't do their job then it could slow everyone else down. Maybe I don't fully understand the question, But I hope its right.