You water three sunflower plants with salt water. Plant A receives a 10% salt solution. Plant B receives a 20% salt solution. Plant C receives a 30% salt solution. A fourth plant, Plant D, receives pure water. All four sunflower plants are grown in identical pots with the same soil content and receive the same amount of sunlight. After a two-week period, the height of the sunflower plant is measured.
What part of the experiment was the salt water?
