Answer:
The correct answer will be- investigation which used the scientific method will be valid.
Step-by-step explanation:
The attempt to answer any natural phenomenon or scientific question uses the scientific approach or method.
If the same scientific question is answered by the two different groups with contrasting or contradictory answers, then the best approach to solve this issue is by reviewing the two explanations by fellow scientists of the peer-review group.
The peer group should check the eligibility of the scientific method to be followed. The group who used the scientific method will be considered valid and the other hypothesis will be rejected.