Concept: Exhaust fumes from electricity generating sets contain poisonous gases that cause serious pollution.Explanation:Electricity generating sets burn fuel, and incomplete combustion produces carbon (II) oxide, which is a highly poisonous gas.Carbon (II) oxide reduces the blood’s ability to carry oxygen, making it a serious pollutant.Water vapour and carbon (IV) oxide are less directly harmful, while ozone is not a major exhaust pollutant from generators.Answer: A. Carbon (II) Oxide