The answer is a because it never needs to be insulated
Greetings!
The correct answer choice is Choice 4.
<em>Why?</em>
In a scientific experiment the only thing being changed is the independent variable. Everything else should stay the same.
In this experiment, the independent variable is the amount of sunlight each plant should receive. <em>Here's a tip</em>- when looking for and independent variable look for whats being changed on purpose.
Hope this helps!
~Fluerie
