Read the passage and answer the following questions :

Air pollutants also deleteriously affect the respiratory system of humans and of animals. Harmful effects depend on the concentration of pollutants, duration of exposure and the organism. Smokestacks of thermal power plants, smelters and other industries release particulate and gaseous air pollutants together with harmless gases, such as nitrogen, oxygen, etc. These pollutants must be separated/ filtered out before releasing the harmless gases into the atmosphere.There are several ways of removing particulate matter; the most widely used of which is the electrostatic precipitator , which can remove over 99 per cent particulate matter present in the exhaust from a thermal power plant . Automobiles are a major cause for atmospheric pollution atleast in the metro cities. As the number of vehicles increase on the streets, this problem is now shifting to the other cities too. Proper maintenance of automobiles along with use of lead-free petrol or diesel can reduce the pollutants they emit. Catalytic converters, having expensive metals namely platinum-palladium and rhodium as the catalysts, are fitted into automobiles for reducing emission of poisonous gases. As the exhaust passes through the catalytic converter, unburnt hydrocarbons are converted into carbon dioxide and water, and carbon monoxide and nitric oxide are changed to carbon dioxide and nitrogen gas, respectively. Motor vehicles equipped with catalytic converter should use unleaded petrol because lead in the petrol inactivates the catalyst. You may ask the question as to why CNG is better than diesel. The answer is that CNG burns most efficiently, unlike petrol or diesel, in the automobiles and very little of it is left unburnt. Moreover, CNG is cheaper than petrol or diesel, cannot be siphoned off by thieves and adulterated like petrol or diesel.

Why CNG is better than diesel ?

All of the above .

The correct answer is Option (4) –All of the above

All of the above points contribute to why CNG (Compressed Natural Gas) is considered better than diesel in many respects:

1. Efficiency: CNG burns more efficiently than diesel, resulting in better fuel economy and lower emissions. This efficiency can translate to cost savings and reduced environmental impact.
2. Cost-effectiveness: CNG tends to be cheaper than petrol or diesel, making it a more economical option for consumers and businesses alike. Lower fuel costs can lead to significant savings over time, especially for vehicles with high fuel consumption.
3. Security: Unlike diesel, CNG cannot be siphoned off by thieves easily. The infrastructure required to access and transport CNG makes it less susceptible to theft, providing a more secure fueling option for vehicles and reducing the risk of fuel-related crimes.

So, indeed, all the points mentioned contribute to the overall superiority of CNG compared to diesel in various aspects.