Which of the following are the reasons/factors for exposure to benzene pollution? [2020]

Which of the following are the reasons/factors for exposure to benzene pollution?

Benzene is a common component in gasoline and is released through automobile exhaust.

Burning varnished wooden furniture and using products made of polyurethane can release benzene and other harmful substances, whereas simply using them does not directly cause major exposure to benzene pollution.

Benzene is a chemical that is a colorless or light yellow liquid at room temperature. It has a sweet odor and is highly flammable. It evaporates into the air very quickly. Its vapor is heavier than air and may sink into low-lying areas. It is formed from both natural processes and human activities.
Natural sources of benzene include volcanoes and forest fires.
Benzene is also a natural part of crude oil, gasoline, and cigarette smoke. Because benzene has a high octane number, it is an important component of gasoline (petrol). Some industries use benzene to make other chemicals that are used to make plastics, resins, and nylon and synthetic fibers. Benzene is also used to make some types of lubricants, rubbers, dyes, detergents, drugs, and pesticides.
Benzene exposure affects the central nervous system and can affect the immune system. Chromosomal abnormalities of bone marrow cells and circulating lymphocytes have been observed in people exposed to benzene.