Answer:
B
Explanation:
BECAUSE TO DO THE TESTS YOU NEED TO DO THE SCIENTIFIC METHOD.
FOR EXAMPLE: OBSERVATIONS AND EXPERIMENTS TO OBTAIN RESULTS.
ANYWAY I LEAVE YOU THE LINK:
https://gscourses.thinkific.com
Explanation:
<h2>Global warming is the unusually rapid increase in Earth's average surface temperature over the past century primarily due to the greenhouse gases released as people burn fossil fuels.</h2>