Coal Mining Is a Dangerous Occupation

Coal mining is a dangerous occupation. Which example correctly depicts the effects of new safety regulations on the negative compensating differential for the job of a coal miner?

A) The passage of workplace safety laws at first increases but then decreases the severity of the negative compensating differential for such a job.
B) The passage of workplace safety laws increases the severity of the negative compensating differentials for such a job.
C) The passage of workplace safety laws decreases the severity of the negative compensating differentials for such a job.
D) The passage of workplace safety laws at first decreases but then increases the severity of the negative compensating differentials for such a job.
E) The passage of workplace safety laws has no effect on the compensating differentials for such a job.