The correct option is
A Observation
The scientific methods are used by the scientists in order to prove a fact. The scientific method is the systematic way to plan work and perform an experiment. The observations are collected and used for investigation of the question. On the basis of these observations, an idea is obtained known as hypothesis which forms the basis of scientific study. The hypothesis is the claim which is set to test the fact and the results are concluded on the basis of the analysis. Thus, the correct answer is option C.