A copper mining operation discharges waste products into a river and causes higher costs and discomfort to downstream users of the water for which they are not compensated. In this case:
there is an external benefit to society from copper production.
too much of society's resources is being used to produce copper.
the optimal amount of society's resources is being used to produce copper.
too little of society's resources is being used to produce copper.

Too much of society's resources is being used to produce copper.

Explanation:

Mining operation is a process whereby the natural resources embedded in the soil are being removed for the usefulness of the populace.

The process of mining involves the degradation of the soil, which can or will render that part of the land almost useless. This means that, the land is inhabitable for most of the natural habitant organisms, and not suitable for agriculture.

The waste products from the mining process are also channeled to water bodies or left unattended to at the mining site, thereby creating pollution to the environment.

In this case, copper mining operation will render the part of the land in the society useless while the waste products channeled to the water creates discomfort to the people residing in the society. This is because, the water won't be useful for domestic purposes and , also kills the organisms such as fish in the water. Therefore, the residents will be forced to look elsewhere for water which is extra cost. And no compensation is given to the society most times.

protectionism fosters competition and keeps price regulated is not an argument in favor of protectionism.