were formed from different fossils took different amounts of time to form formed at different times formed by different methods
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Limestone is a sedimentary rock and marble is a metamorphic rock. Even though limestone and marble have the same chemical makeup, they are classified as different rocks because they
Possibilities:
- were formed from different fossils
- took different amounts of time to form
- formed at different times
- formed by different methods

formed by different methods