Answer:
Form a hypothesis
Step-by-step explanation:
Scientific Method is the methodology used by scientists in the pursuit of knowledge, in a more precise definition: a set of ground rules for developing an experiment to produce new concepts as well as correcting and integrating pre-existing knowledge.
The method begins with the observation by the scientist, he detects something to be investigated (physical, biological or chemical phenomenon) and starts to problematize, why the event. Then a hypothesis (an answer) arises for the phenomenon, it must be based on quality science. If the hypothesis is approved by the judging committee (formed by scientists) it becomes law, as happened with Lavoisier's law.
In the case exposed in the question above, we can see that the researcher observed something to be investigated, which was the influence of the colors of the moths to be observed on a white background. The next step for the researcher is to form the hypotheses and then come to a conclusion.