17. The products of combustion of marine fuels include sulfur dioxide, which, when combined with water vapor, forms acids such as the sulfurous acid and sulfuric acid. These acids cause cold-end corrosion if allowed to condense on boiler components of flue gas ducting. Therefore, in order to prevent the cold-end corrosion, which action is not to be taken? (A) To ensure the temperature of exhaust gas is always above the condensation temperature level. (B) To install more heat exchangers in the flue gas ducting so that the temperature of exhaust gas is further reduced. (C) To prevent any chemical process that formulates the acid within the boiler components of flue gas ducting. (D) To ensure there is no water-vapor condensate formed within the flue gas by controlling the flow temperatures in the flue-gas ducting.