The answer is A
Using energy
The common component of air pollution is particulate matter (PM). This is a complex mixture of extremely small particles and liquid droplets.
The major components of PM are sulphates, nitrates, ammonia, sodium chloride, black carbon, dust particles and water. PM comes from dust , soot, smoke, industry and vehicle exhaust as well as complex chemical reactions with other pollutants.
Burning of fossil fuels produces sulphur dioxide . It is a colorless gas that pollutes the air and can cause health problems affecting the respiratory system.
<span>Cancerous tumors are divided into broad groups on the basis of the particular type of tissue from which the tumor cells arise. this is called histogenesis.
</span><span>Tumors are of different types, some are cancerous and some are benign (non-cancerous). In a disease of cancer, there is an abnormal cell growth. It is characterized as out of control cell growth.</span>
The answer to this one is the first one