In Order to Answer the Given Question, Which of the Following

In order to answer the given question, which of the following types of study would be the most appropriate: anexperiment without blinding, an experiment with single blinding, an experiment with double blinding, an observationalstudy, or a case-control study?
-In which of these four soil types will the plants grow fastest?

A) Experiment with single blinding
B) Observational study
C) Experiment with double blinding
D) Experiment without blinding
E) Case-control study