Choose the word or phrase among A, B, C or D that best fits the blank space in the following passage

There are various types of pollution in the world. The most (1) ____________ one is air pollution. It is caused mostly by factories which exclude smoke. This smoke pollutes the atmosphere (2) ____________ dust and cinder which can cause various types of diseases like lung cancer, heart failure and sinus infection when inhaled. Carbon monoxide from exhaust pipes of vehicles is also very dangerous and can cause instant death when inhaled in (3) ____________ amount.

 Water pollution is the pollution that occurs in rivers, seas, oceans, lakes and other waterways. Water pollution is normally caused by the (4) _________ of waste like garbage and feces. The marine life in these waters will be affected. Some the toxic extracts of the poisonous sea creatures perish while others store the toxic extracts of the poisonous waste in their fat glands.  When human beings eat these creatures, they will either fall ill or die. In Japan alone, every year, thousands of people suffer (5) _________ strange diseases due to mercury poisoning. Others either lose their mental capacity or meet their deaths.

There are various types of pollution in the world. The most (1) ____________ one is air pollution.