Biology

The correct answer is: D.Salt Water.

Salt water itself is not typically considered a pollutant. It is the natural water found in oceans and seas. However, when salt water is introduced into freshwater systems through processes like saltwater intrusion (often caused by overuse of groundwater or rising sea levels), it can contaminate freshwater sources, but salt water itself is not inherently a pollutant.

Here’s why the other options are pollutants:

A.Toxic chemicals: These include pesticides, heavy metals, and industrial waste that can contaminate water a...