Here's a problem to solve: Joann is testing soils to see which kind is best for growing marigolds. Which of the following should she do?

Among the 4 following options, which is the correct answer?

- A: Plant the marigolds in the same soil, but water some plants more than others.
 
- B: Plant the marigolds in one kind of soil, radishes in another, and daisies in a third kind.
 
- C: Plant the marigolds three kinds of soil, and give them different amounts of sun.
 
- D: Plant the marigolds in three kinds of soil, and give them the same amounts of water and sun.
 