Answer: b) Data mining
Explanation: Data mining is the process in which the raw data is converted into the useful and meaningful information to be used by the organizations. Huge data is analyzed by the companies for business purpose for marketing, learning about customers, development of sales and etc.
Walmart is also using this system so that they can know about their customers, their purchase, ordering the vendors to create the reorders etc.
Other options are incorrect because data isolation is face in concurrency activity, secondary data collection is data gathering by someone other than the user. sentiment mining is extracting opinion and qualitative research is collection of non -numerical data and then analyzing it.
Thus, the correct option is option(b).