Respuesta :
A possible source of additional salt in the stream is the influence of the ocean upstream.
The map shows the course of the Mississippi River through the states of Minnesota, Wisconsin, Iowa, Illinois, and Missouri and its mouth in the Ocean.
According to this information, the salinity detected in South Dakota of the Mississippi River can be caused by the influence of the salty water of the Ocean against the current of the river.
Note: This question is incomplete because the map is missing. Here is the map.
Learn more in: https://brainly.com/question/21554509

Answer: C. Nearby Franking
Explanation: Someone in the comments was helpful enough to say it but couldn't post it so yea, just passing it on but its right so thanks to them