In the following paragraph, which sentence should be rewritten in active voice?

A cure for the disease was found in a recent study. A medicine was created using natural materials. First, a blend of herbs is mixed with milk. The mixture is then consumed to start the healing treatment.

A. First, a blend of herbs is mixed with milk.
B. None of these should be rewritten.
C. A medicine was created using natural materials.
D. The mixture is then consumed to start the healing treatment.