Question

what is the thing being changed to test in this experiment? (whats his test or independent variable?) amount of sunlight amount of water type of soil type of plant

Explanation:

In an experiment, the independent variable is what is changed to test its effect. Here, any of the options - amount of sunlight, amount of water, type of soil, type of plant - could potentially be the independent variable depending on the experiment's focus.

Answer:

All of the above could be the independent variable depending on the experiment's design. So the options are:
A. amount of sunlight
B. amount of water
C. type of soil
D. type of plant