Optical microscope.
Hope this helps.
Answer:
B. only the animals living in water
The results of the study would be expected to change if the same experiment were repeated with natural gas in the area of a decrease in the reaction time.
<h3>What is Reaction time?</h3>
This is the time frame between when a stimulus and a response or total time taken for a reaction to occur.
Natural gas produces steady amount of heat with a higher temperature which leads to a decrease in reaction time.
Read more about Reaction time here brainly.com/question/1114291
