Alex wants to find out if different amounts of water affect plant growth. She waters three bean plants with three different amounts of water. She measures each plant’s height daily. She places all three plants in the same window to get sunlight. She keeps the temperature in the room set at 72°F. Which option is the responding variable in this experiment?
A. the amount of sunlight
B. the temperature of the room
C. the height of the plants
D. the amount of water