A large company wants to compare two incentive plans for increasing sales. The company randomly assigns a number of its sales staff to receive each kind of incentive and compares the average change in sales of the employees under the two plans. Is this study a survey, an experiment, an observational study, or a case study?

Answer:an observational study

Explanation:An observational study is a study where a researcher collect the infomation or data from their observation, based on what they see or hear but a researcher doesn't control or interfere or try to manipulate the study. A researcher observes and record what they see as they see it, this method observe subjects in their natural environment because it is believed that participantsor subjects can portray their true behavior when they are observed in their natural environment.