core mantle atmosphere hydrosphere
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The Late Heavy Bombardment was a period of extensive comet impact on Earth about 3.8 billion years ago. Scientists believe this period provided much of the matter now found in which part of the Earth system?
Possibilities:
- core
- mantle
- atmosphere
- hydrosphere

hydrosphere