A statement proposed before the experiment related to the natural phenomenon which explains the event to a limited extent is known as the scientific hypothesis.
The scientific hypothesis when tested and proved by the researcher and fellow researchers many times transforms the hypothesis either to a scientific law or theory.
The scientific law is a statement which can contain quantifiable variables which describes the pattern and behavior of the natural phenomenon but do not explain why this behavior is observed which in turn is explained by the scientific theory.
Law would be the correct answer to fill in the blank. Law is correct because scientific law explains behaviors of natural phenomenons since it's based on repeated experiments.