Question

e. what factors would you need to keep the same or control, as you change the light intensity applied to the earthworm?

Explanation:

In an experiment with earthworms and changing light - intensity, factors like temperature of the environment, humidity of the soil they are in, the type of soil (composition and texture), the size and age of the earthworms, and the time of day (as earthworms may have circadian - related behaviors) should be kept constant to ensure that any observed changes are due to light - intensity variations.

Answer:

Temperature, humidity, soil type, earthworm size and age, time of day.