I think "that" is the adjective clause because you can remove it without ruining the sentence.
It means dispute because if you read over all the other answers that is the only one that makes since
The difference between science and pseudoscience is that science organizes knowledge in testable explanations and predictions about the universe while a pseudoscience is is a claim or a belief which is carried out as scientific but has no valid [ scientific method, not reliably tested. ]
Psychology is considered a social science, yet it has foundations in the natural sciences.
Psychology is considered a social science, yet it has foundations in the natural sciences.
