Which of these is designed by researchers to test only a single prediction of a hypothesis at a time?

Question

Which of these is designed by researchers to test only a single prediction of a hypothesis at a time? ​

Quizplus · Accepted Answer

A controlled experiment is designed by researchers to test only a single prediction of a hypothesis at a time. It involves manipulating one variable and keeping all other variables constant, in order to determine the effect of the manipulated variable on the outcome. This allows researchers to test specific predictions of their hypothesis and determine causal relationships between variables. The other options listed (B, C, D, and E) are all components of a controlled experiment or scientific study, but do not specifically refer to the design of testing single predictions of a hypothesis.

Which of These Is Designed by Researchers to Test Only