Question 1 of 10 Only an experiment can prove: A. effectiveness. B. causation. C. a relationship of any kind. D. a biological basis.

The correct answer is:<br /><br />**B. causation.**<br /><br />### Explanation:<br />An experiment is the only research method that can establish **causation**, meaning it can demonstrate that one variable directly causes a change in another variable. This is because experiments involve manipulating an independent variable and observing its effect on a dependent variable while controlling for other factors. Other research methods, such as correlational studies, can show relationships or associations but cannot prove causation.