Air is a natural resource and cannot be exhausted by human activities. It is known as inexhaustible natural resource. Which of the following is another inexhaustible natural resource?
Inexhaustible resources are the ones present in unlimited quantity and cannot be exhausted by human activities. Air and sunlight are examples of inexhaustible resources. Coal, petroleum and minerals could be exhausted in the coming future due to continuous use and limited availability. Therefore, they are not inexhaustible.
Hence, option C is correct here.