Air Pollution

Electrostatic precipitators use the principle of electrically charging particles in an exhaust and then allowing them to settle on variably charged platforms. It is done primarily for control of SPM or suspended particulate matter such as dust, fumes, smoke etc.

PM or particulate matter of diameter $2.5\,\,\mu$m or less is the most harmful as they are inhaled deep into the lungs causing serious lung damages, deposition in respiratory tracts and even death of the person.

Forests act as natural filters for air pollution, as trees and leaves capture particulate matter and absorb various gaseous pollutants from the atmosphere.

The aircraft or jet planes engine emit certain particles and gases like carbon dioxide, hydrocarbons, nitrogen oxides, lead, black carbon, aerosols etc. These are basically greenhouse gases and anthropogenic compounds which have the tendency to react among themselves and with gases present in the atmosphere. Greenhouse effect, ozone depletion activities can be related to the emission of these gases. 

Scrubber separator is a type of dust separator device and not particulate matter separator.

A catalytic converter is an emissions control device that converts toxic pollutants in exhaust gas to less toxic pollutants by catalyzing a redox reaction 

Incinerators are used to burn garbage which produces toxic ash, nitrogen oxides, carbon dioxides etc and thus, contributes to the air pollution. This method is mainly used to reduce solid wastes. Using renewable energy like solar and wind energy are the natural energy source that does not contribute to the air pollution. Catalytic converters reduce air pollution as it converts the harmful gas into the useful like it converts the carbon monoxide into the carbon dioxide which then absorbed by the plants. Thus, the correct answer is option B.

Pollution is the addition of contaminants in the environment which degrades its quality. The air pollution is the major threat which needs to be regulated. A catalytic converter is a device used to reduce the emissions from an internal combustion engine (automobiles and vehicles). Enough oxygen is not available to oxidize the carbon fuel in these engines completely into carbon dioxide and water; thus toxic by-products are produced. Catalytic converters are used in exhaust systems to provide a site for the oxidation and reduction of toxic by-products (like nitrogen oxides, carbon monoxide, and hydrocarbons) of fuel into less hazardous substances, such as carbon dioxide, water vapour, and nitrogen gas.

Adsorption is the phenomena where the atoms, ions or molecules from the gases, liquid and solids to a surface. It is a surface-based phenomenon and it easily absorbs the gas molecules and can reduce gaseous pollutants.

The electrostatic precipitators work on the principles of the electrostatic force. It consists of discharge wires and collecting plates. An application of high voltage to the discharge wires create an electric field between the wires and the plates. When the air containing the dust and suspended particulate matter like aerosols and solid particles is passed through this electrostatic field, the particles get charged and are collected onto the plate as per Coulomb's Law. This makes the air free of dust and SPM. Electrostatic precipitators are used in vehicles and coal-fired power plant to restrict the entry of dust and SPM into the atmosphere

Air pollution is caused by the release of harmful oxides of nitrogen, sulphur and carbon from the vehicular exhausts and industrial emissions primarily. Using precipitators allow the removal of dust from these emissions. Keeping the air clean by minimizing the combustion of fossil fuels, less use of vehicles, use of catalytic converters can help in reducing the air pollution. Reusing waste allows the minimal production of non-degradable waste. Hence, the correct answer is 'Reusing wastes'.