Final answer:
Potentially responsible parties (PRPs) related to the cleanup of contaminated sites are least likely to be real estate licensees since they are not typically owners or operators involved in hazardous waste activity.
Step-by-step explanation:
Potentially responsible parties (PRPs) in the context of environmental law and cleaning up hazardous waste sites are least likely to be real estate licensees. This is due to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), better known as Superfund.
The Superfund assigns liability for the cleanup of contaminated sites primarily to four groups of parties: current owners of the site, operators of the site at the time of disposal, past owners at the time of waste disposal, and those who arranged for the disposal of a hazardous substance.
Real estate licensees typically facilitate the transaction of properties but are not directly involved in the operations or ownership where the environmental contamination occurred. Nevertheless, it is important to note that liability under CERCLA can extend to a wide array of associated parties; however, real estate licensees are not typically the frontline PRPs in cases of environmental cleanup and liability.
Therefore answer is A. present owners.