A is your best choice from this list. A counfounding variable can occur when you cannot distinguish between multiple variables because of a lack of or error in establishing a control group. https://study.com/academy/lesson/confounding-variables-in-statistics-definition-examples.html...
What are confounding variables?Question:What are confounding variables?Variables:Variables are anything that has an amount or characteristic that varies. In research, these variables can be independent, dependent, confounding, extraneous, and moderated.Answer and Explanation: Become a Study.com member to...
What are the independent and dependent variables in a study? What was the dependent variable in Monster Study? What is a good example of a positive and negative correlation in psychology? Does one variable cause the other and is it possible to have a third variable?