CR-gmatprep

Some more detail and explanations with your answer choice please.

This is a question about averages and about ratios: the average reclamation cost per ton of coal produced is lower now than 20 years ago. So either the average cost of reclamation has gone down, or the tonnage of coal produced has gone up (or both). B might look tempting, but it weakens the argument: it tells us that less coal is produced, which should make the cost per ton go up, not down. The operating costs of running a mine, or the proportion of mines of different types in Balzania, are not relevant here, so A, D and E are out. C should be the answer: if 20 years ago, some mines were very expensive to reclaim, and those mines no longer exist, the average reclamation cost should be lower now than before - take the largest values out of a set and the average will drop.

Wow, great pick.

I also chose C

IMO C

Focusing on other areas has kead to the reduction. Whats the OA

This is my take:
Since avg cost per ton has decreased. This is possible if either cost as decreasd or coal mined has increased over 20 yrs. Now E says that coal mined from surface mines has increased over 20 yrs.so avg cost per ton has decreased.
Study can u post the OA now?

Agree with C. If high reclamation cost component is eliminated, the average reclamation cost will come down.

oops....I didnt pay attention to mountainous area in C which was responsible for high reclamation cost.
Yup It sld be C