Jimmy put some dirt and water into a jar, put the lid on, and then shook the jar. The contents of the jar turned brown. Jimmy set the jar on the table and checked back every 5 minutes for 20 minutes. The pictures show what Jimmy saw. Which of the following best explains what happened in the jar after 20 minutes?

A. The dirt and water combined to form new compounds.
B. The water and dirt combined to form a heterogeneous mixture.
C. The water dissolved some of the dirt particles, creating a solution.
D. The dirt broke down into elements and settled in the jar according to density.