Answer:
The correct answer is:
1. tertiary source
Step-by-step explanation:
Since the experiment was reported for the first time by the researchers directly who would represent the primary source, the magazine article would be the secondary source because it would sintetize the information found by the researchers that has been already embodied in their research investigation report. And finally the report of the magazine would represent the tertiary source because it is using the magazine as the secondary source to check for the information regarding the investigation.