Answer :
(A) is incorrect because that new discovery could be true. The scientist would have to conduct multiple trials under a multitude of conditions to ensure its validity, however. (C) is incorrect because long-accepted theories are often backed with lots of evidence and by changing it, his observations haven't yet been accepted and no one would believe him. (B) is correct because he should analyze and compare his findings with findings already accepted within the scientific community. (D) is incorrect because theories must be backed with lots of evidence, and he would have to conduct more trials in order to be able to create a theory. I hope this helps!