I'm not an expert on this but I'm speculating "fracking"
Which uses high water pressure to extract the coal.
The answer will be D because if there is a purpose behind an issue it can help provide examples and backup.
At least to me
With steerage from the expert, the intervention affords a planned possibility to provide help and result in the desired changes. An intervention may be direct or oblique.
Answer:
body having the property of attracting iron and producing a magnetic field external to itself specifically : a mass of iron, steel, or alloy that has this property artificially imparted. 2 : something that attracts a box-office magnet.