(B) At least as many passenger jets were produced by the division last year as had been produced in 1994.
If a significantly higher number of jets were produced last year, possibly the number of workers would also need to increase substantially. This escalation in production would likely lead to a rise in the total hazardous waste output, exceeding 50% of 1994 output.
(D) The average number of weekly hours per production worker in the passenger-jet division was not significantly greater last year than it was in 1994.
the equation the stem gives is: # of workers * average hazardous waste output per worker = total hazardous waste output
(E) The number of production workers assigned to the passenger-jet division was not significantly less in 1994 than it was last year.
If the number of workers was significantly lower in 1994 than last year, the total output of hazardous waste would also be lower.
However, that was not the case; the number of workers remained relatively constant. This indicates that the company has indeed met its goal.