uses more than one caterpillar. performs the investigation on a wet surface. uses earthworms instead of caterpillars. performs the investigation at the same time on four days.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student investigates the effect of temperature on the distance a caterpillar travels in one minute. The student performs the investigation at four different times of day using one caterpillar. This experiment could be improved if the student
Possibilities:
- uses more than one caterpillar.
- performs the investigation on a wet surface.
- uses earthworms instead of caterpillars.
- performs the investigation at the same time on four days.

uses more than one caterpillar.