The text directly addresses this point by stating theres no baseline and changing criteria and design thats not necessarily true right if we want to know where to start our criterion well a baseline is going to be helpful so c is going to be false Therefore the statement that a baseline phase is never included is incorrect While not always strictly mandated a baseline phase is highly recommended and frequently implemented in a changing criterion design It helps establish the initial stable level of the target behavior before any intervention is applied providing a clear starting point for setting the first criterion and making it easier to evaluate the impact of the intervention Options A and B are true varying the magnitude of criterion changes and increasing the number of criterion changes helps to strengthen the internal validity of the design by demonstrating that behavior changes systematically and predictably with each criterion shift ruling out confounding variables Option D is also true allowing the behavior to stabilize within each criterion phase is crucial This steady state ensures that any subsequent behavior change can be confidently attributed to the new criterion rather than to ongoing variability or extraneous factors