Most of the major health problems in poorer nations are due to ______.

• A. Parasitic worms and microorganisms
• B. Psychological tension resulting from work
• C. Air pollution
• D. Water pollution

Answer: (A)

The main idea is that in poorer nations, the biggest health burden comes from infectious diseases caused by parasites and microorganisms. In settings with inadequate sanitation, unsafe water, and crowded living conditions, parasitic worms (like hookworm and roundworm) and a host of microbes spread widely, leading to common illnesses such as diarrheal diseases, malaria, and other infections that cause a large share of morbidity and mortality, especially among children. While other factors like pollution can worsen health, they don’t account for the broad, dominant pattern of illness driven by infectious diseases in these environments.