Environmentalist: An increased number of oil spills and the consequent damage to the environment indicate the need for stricter safety standards for the oil industry.
Environmentalist's Conclusion
The national government must regulate industry safety standards, or at a minimum at least require oil companies to put double hulls on their tankers and to assume financial responsibility for accidents.
Environmentalist's Evidence (since)
There have been damaging spills from the oil industry, and the oil industry refuses to take action.
Industry Rep's Conclusion
The industry alone should be responsible for devising safety standards.
Industry Rep's Evidence (because)
The industry has expertise in handling oil and understands the cost entailed. The double-hull proposal is not feasible, because it creates new safety issues, and the cost would be burdensome to the industry and to consumers.
Evaluate
We need an answer that helps out the industry rep, so we want to reinforce ideas like, - the government should not be the one to set safety standards / industry should - industry knows more about this stuff - the double-hull solution is not a feasible solution (too costly to industry and consumers, and creates safety issues)
Goal
The correct answer is hard to predict here, so let's just look for something that the industry rep could say to add on to her argument or to better shoot down something that the environmentalist said.