What do scientists need to look at before developing an argument?
the validity of data, claims, hypotheses, and observations.
their opinion and personal views.
the arguments of famous people on the topic.
the arguments that make the most sense for society.

I believe the correct answer from the choices listed above is the first option. The scientists need to look at the  validity of data, claims, hypotheses, and observations before developing an argument. They base their arguments on facts that are present and they make sure they have proofs. 

The validity of data, claims, hypotheses, and observations.