Question

the most widespread source of water contamination in developing countries is ______. raw sewage toxic chemicals oil radioactive substances

Explanation:

In developing countries, due to lack of proper sanitation and sewage - treatment infrastructure, raw sewage is a very common source of water contamination. Toxic chemicals, oil, and radioactive substances are also sources of contamination but are not as widespread as raw sewage in developing countries.

Answer:

A. raw sewage