the shale layer is older than the limestone layer. a fault occurred during the deposition of the layers. the environment changed between the times of deposition. volcanic activity occurred when these layers were deposited.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A road cut shows a layer of shale on top of a layer of limestone. This indicates
Possibilities:
- the shale layer is older than the limestone layer.
- a fault occurred during the deposition of the layers.
- the environment changed between the times of deposition.
- volcanic activity occurred when these layers were deposited.

the environment changed between the times of deposition.