Final answer:
Paul should report the leak to the Minnesota Pollution Control Agency (MPCA) immediately.
Step-by-step explanation:
The correct action that Paul should take in this situation is A. Report the leak to the Minnesota Pollution Control Agency (MPCA) immediately.
When hazardous materials leak into the environment, it is important to report the incident to the appropriate regulatory agency. In this case, the MPCA is the designated authority for handling environmental incidents in Minnesota. They will be able to assess the situation, provide guidance on cleanup procedures, and ensure that the proper measures are taken to protect both human health and the environment.