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
Yes, it is <span>accurate to describe the physical universe as composed of only matter and energy. Some people might argue about the dark matter, but it is not yet defined properly. Different universes can be made up of different compositions but it is a fact that our universe is made of matter and energy. </span>