Answer:
A. Large amounts of water force open cracks in rocks
Explanation:
Hydraulic fracturing, or fracking, is a drilling method used to extract petroleum (oil) or natural gas from deep in the Earth. In the fracking process, cracks in and below the Earth's surface are opened and widened by injecting water, chemicals, and sand at high pressure.
A is basically explaining this the same way. Forcing cracks in the ground with liquids.
Hopefully I was a help to you. If not I am sorry and I wish you the most wonderful of days. :)