direct observation of the important properties of the Earth system controlled laboratory experimentation on a simulation of geological systems methodical testing of a valid hypothesis statement inquiry into the causes of observed geological phenomena
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: The discovery of tectonic plates and the cause of their movement is best described as a result of which scientific procedure?
Possibilities:
- direct observation of the important properties of the Earth system
- controlled laboratory experimentation on a simulation of geological systems
- methodical testing of a valid hypothesis statement
- inquiry into the causes of observed geological phenomena

inquiry into the causes of observed geological phenomena