Which of the following are the reasons/factors for exposure to benzene pollution? 1. Automobile exhaust 2. Tobacco smoke 3. Wood burning 4. Using varnished wooden furniture 5. Using products made of polyurethane Select the correct answer using the code given below:

The correct answer is (D) because benzene is a volatile organic compound (VOC) emitted through both the combustion of organic materials (automobile exhaust, tobacco smoke, and wood burning) and the off-gassing of synthetic household products like varnishes and polyurethane. Option (a) is the most tempting wrong choice as candidates often focus exclusively on high-profile combustion sources while overlooking the significant role of indoor chemical emissions from furniture and plastics. The core concept tested is the identification of diverse anthropogenic sources of hazardous air pollutants in both outdoor and indoor environments.