A resident living near a factory brought a private nuisance action against the factory, alleging that emissions from the factory's smokestack were aggravating her sinus condition and interfering with the use and enjoyment of her property. What is the most relevant factor in the factory's defense of the lawsuit?
a) The plaintiff moved to her current residence after the factory's smokestack was releasing that level of emissions.
b) No other residents of that neighborhood have complained about the factory.
c) The factory complies with local zoning ordinances.
d) No particulate matter from the emissions has landed on the plaintiff's property.
