Pollution from a factory that produces cleaning products is a(n)
tariff
antitrust law
externality

The right option is; externality

Pollution from a factory that produces cleaning products is an externality.

An externality is the effect of an economic activity that is encountered by unrelated third parties. An externality may be positive or negative. An example of a positive externality is the effect of a highly skilled labor force on the productivity of an organization while an example of a negative externality is the pollution released from a factory that destroys the environment and affects the health of people living in the environment.  

well since twins have about the same dna they dont have one think in common which is the figer print. nobodys fingerprint is the same. if your using twin you would most likely get around the same results for both of them because of the genetics.. i hope this