Answer:
C. It will produce the good above the socially efficient level.
Explanation:
The socially efficient level of production is reached where marginal/total costs of production equals marginal/total benefits of production.
A negative externality is a cost that is not reflected in the price of goods if left to market forces alone.
Therefore, producers will over-supply to the level where the only their costs of production (equals total social costs minus cost of negative externality) equals total benefits to society (indicated by demand).