Adesign in which measures are taken at baseline and after the introduction of the independent variable at different times across multiple situations is a multiple-baseline design. time

settings

Explanation:

This is a type of design in which there is an application of treatment to the same subject across different situations, time or settings. Usually the procedure starts with the baseline where there is no inteventions(treatment of subjects), then the treatment is then introduced. There may be no need for the withdrawal of interventions afterwards under the multiple-baseline across settings design, instead there is a transfer of treatment to another subject to determine the effectiveness of treament.  

"choosing is refusing" means individuals face an opportunity cost with each decision they make. economists state that every decision involves trade-offs. opportunity cost is the least desirable alternative given up as a result of a decision.