Are dogs better pets than cats? How many stars are in the universe? In what type of light will a plant grow best? How many organisms have lived on Earth?
Which question can be answered by scientific experimentation and observation?

Options:
- Are dogs better pets than cats?
- How many stars are in the universe?
- In what type of light will a plant grow best?
- How many organisms have lived on Earth?

In what type of light will a plant grow best?