If the __ cost for producing a particular good is lower for one producer than another the former producer has for producing the good

Opportunity cost / relative advantage

Explanation:

Opportunity cost is one way of measuring the cost of a producer's choice of production. For example, if a producer chooses to produce soybeans, the opportunity cost is what he fails to earn if he produces another good, for example corn. In this way, opportunity cost is a relative measure of costs. If the opportunity cost for a producer to produce a good is lower than for another producer, this means that he has a comparative advantage in producing that good.

Having the comparative advantage over the production of a particular good is a good indicator for the productive choice. The country with a comparative advantage can specialize in the production of the good in question and profit from international trade through exports.

I Believe the answer is: Iron and coke (low-sulfur coal).

For the past decades, Iron and coke (low-sulfur coal) industry in Mexico has shown a healthy average of 6% Growth annually.
Because of the resources in Iron and coke (low-sulfur coal), Mexico has always maintained the top 15 steel producers in the world.