the answer is actually A. chemical weathering by oxidation .
chemical weathering works on rocks that contain iron. These rocks turn to rust in a process called oxidation. Rust is a compound created by the interaction of oxygen and iron in the presence of water.
3. IV:height of drop DV:height of bounce CV: type of ball, place where ball is dropped, climate/wind
4. IV: battery type DV: time that it lasts CV: age of batteries, age of material (flashlights), type of materials (flashlights), size of batteries
5. IV:depth of water DV: temperature CV: amount of water in lake, temperature, climate/season
Answer:
is about 4.6 billion years old