People and animals living in low-lying areas of lake nyos in cameroon, africa, were killed after carbon dioxide escaped from the lake and moved across the land. this is an example of a. how human activities can affect humans and the environment b. the fatal consequences of industrialization c. how natural processes can introduce harmful materials into the environment d. the dangerous effect of livestock competition

The correct answer is C.
According to the scientific community, this is an example of a limnic eruption. Limnic eruption is a type of natural disaster which involves the eruption of dissolved carbon dioxide from deep lake waters. This natural process causes the formation of a gas cloud above the wide lake area which can suffocate humans and animals living there. It is believed that the eruption of carbon dioxide can be triggered by earthquakes, volcanos or explosions. 

Cis your correct answer