Answer:b.hypothesis
Explanation:the formulation of hypothesis is one of the steps of scientific method.
It is a process scientists used to investigate an occurrence and construct an accurate interpretation.
Observation about a phenomenon is made before an hypothesis is formulated.
The hypothesis is then investigated using experiments.
When it is right ,further experiments are carried out.
But when the hypothesis is wrong,that is the experiments does not confirm it true,the hypothesis will be cancelled or modified