This is a tough one. It smells like a LSAT questions! If not, I won't
worry too much. Lot of loose ends!!
The choices are B and C.
Price stability will be reached either by reduced sales of higher priced
item or increased supply of lower priced item.
Assume that the overall demand stays the same, then one can't lower the
import from Mexico. Only way is to substitute Mexico oil for some other
country oil. So, other countries must be in a position to supply oil for
the original price.
In this scenario, the answer B makes more sense.
Assume that demand is elastic, then any increase in price results in
decresed demand. In this scenario, the highest priced supplier suffers the
most and answer C makes sense.
Well, In CR, one should not assume other than what has been stated.
Going by the rule, I don't know what to choose.
But, if one can use the external knowledge, then I would go with C.