Question

samanthas urban community is blanketed with smog. which statement best explains the reason for this poor air quality?
people crowd sidewalks as they walk to shopping malls.
people use underground subways for long - distance travel.
people ride bicycles to commute to work on a daily basis.
people drive cars whenever they need to go somewhere.

Explanation:

• People walking to malls (first option) doesn't directly relate to air - quality issues from emissions.
• Subways (second option) are a relatively clean form of mass - transit and don't contribute much to smog.
• Bicycles (third option) are non - polluting.
• Cars (fourth option) emit pollutants like nitrogen oxides and volatile organic compounds which contribute to smog formation.

Answer:

People drive cars whenever they need to go somewhere.