Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs when the shell develops a nasty slime and gives off a horrible odor. His friend Patrick tells him that rubbing seaweed on the shell is the perfect cure. Sponge Bob decides to test this cure by rubbing Gary with seaweed for 1 week. After a week of treatment, the slime is gone and Gary’s shell smells better. What is the dependent variable in this experiment?