The Biocarb Company wants to build a sterilization plant to treat contaminated medical waste in a city neighborhood where residents and environmental activists fear that such a facility will pollute the area. Biocarb' s president argues that the operation of the plant cannot cause pollution because the waste would be sterile after processing by the plant. He claims that after exposure for an hour to superheated steam in the autoclave, such refuse would be far cleaner than food prepared in the cleanest kitchen. The president's argument depends on which one of the following assumptions? ['Treatment by superheated steam represents the surest method of sterilization.', 'Fear of pollution is the only argument against construction of an autoclave facility for medical waste.', 'No others besides environmental activists are concerned about pollution hazards that can result from processing medical waste.', 'Handling of the waste before treatment in the proposed facility will not pose a threat of pollution to the area.']