Aradio station asks its listeners to call in their opinion regarding the use of pesticides in residential areas. what type of sampling is used?

You have just been hired as a brand manager at kelsey-white, an american multinational consumer goods company. recently the firm invested in the development of k-w vision, a series of systems and processes that allow the use of up-to-date data and advanced analytics to drive informed decision making about k-w brands. it is 2018. the system is populated with 3 years of historical data. as brand manager for k-w’s blue laundry detergent, you are tasked to lead the brand's turnaround. use the vision platform to to develop your strategy and grow blue’s market share over the next 4 years.