Research that is designed to capture cause-and-effect relationships by eliminating competing explanations of observed findings is known as _.

^^^^^^^^^^^b.^^^^^^^^^^^^^^^

Experimental research is generally recognized as the most appropriate method for drawing causal conclusions about instructional interventions, for example, which instructional method is most effective for which type of student under which conditions. In a careful analysis of educational research methods, Richard Shavelson and Lisa Towne concluded that “from a scientific perspective, randomized trials (we also use the term experiment to refer to causal studies that feature random assignment) are the ideal for establishing whether one or more factors caused change in an outcome because of their strong ability to enable fair comparisons” (2002, p.110). Similarly, Richard Mayer notes: “experimental methods— which involve random assignment to treatments and control of extraneous variables—have been the gold standard for educational psychology since the field evolved in the early1900s” (2005, p.74). Mayer states, “when properly implemented, they allow for drawing causal conclusions, such as the conclusion that a particular instructional method causes better learning outcomes” (p.75). Overall, if one wants to determine whether a particular instructional intervention causes an improvement in student learning, then one should use experimental research methodology.

Read further @ http://www.education.com/reference/article/experimental-research/

Option b is the right answer.................

I agree with all      B. experimental research 

Agreed by experts views ............................

.............................B. experimental research

Answer B) Experimental research 

as referenced to : Marketing Management:14th Edition -  By Philip Kotler, Kevin Lane Keller 

It is a good question, as first impressions would be "Observation Research"; this is a process in the Experimental research, and its findings are put forward for to define the "controlled Variables".

A) Observational research, attend every detail and focus on the objective to study.

>>>>>>>>>>> B. experimental research. >>>>>>>>>>>>>>

I think the answer is : B. experimental research