This is a hypothesis. A hypothesis is simply a scientific guess to explain a particular phenomenon. It provides different approaches to which an observation can be verified and properly ascertained.
If we can deduce a pattern from a set of experimental data that we have but we have not explained why the observations occur, this is still within the phase of the scientific method called hypothesis.
The experiment is performed to test a tentative explanation or hypothesis which explains the process to a limited extent. The hypothesis when proved through repeated experiments gets transformed either in the scientific law or the scientific theory depending on the quantitative measurement.
The scientific law represents the description of any natural phenomenon by providing the mathematical expressions but it does not provide an explanation to the natural process as provided by the scientific theory.
Since the statement does not provide the explanation but only the description of the natural events therefore, a scientific law is the correct answer.
