Which of the Following Is an Example of Pollution

Which of the following is an example of pollution?

A) Turkeys enter a field and eat some of the seeds scattered on the ground.
B) A heavy rain occurs, resulting in some ponding of water.
C) Small amounts of iron leach from rocks in a streambed, increasing the amount of dissolved iron in the water.
D) Leftover minerals from ores are left along a streambed, allowing leftover traces of the mineral to run off into the stream after heavy rains.
E) Deer cross a stream, disturbing the sand and silt on the streambed, making the water muddy and cloudy.