C. Fishing
I think fishing would make sense due to living in a river valley.
Answer:
Index fossils, intrustions and cross-cutting relationships.
Explanation:
The correct list of three different geologic features that help scientists determine the relative ages of rocks by their position is "index fossils, intrusions, and cross-cutting relationships".
Answer: 1: Likely have some basis in truth
2: very important
Explanation: