A. Oil refineries and factories
B. Vehicular emissions
C. Volcanic eruptions
D. All of these
🧠 Explanation:
Air pollution sources include vehicles, industries, and household activities, covered by “all of these.” This issue is a key topic in environmental science, engaging students and activists. Understanding pollution sources clarifies their impact on health and climate, relevant for sustainability studies. Their variety attracts those exploring environmental solutions, highlighting the need for cleaner technologies and policies, emphasizing their role in improving air quality globally.
