Select one (or more) of the following agile development comp

Select one (or more) of the following agile development components of the XP approach:User storiesRefactoringTest-first/Test driven developmentPair programmingDescribe the component in detail and provide background on its use.Compare and contrast the pros and cons of the component.Select one of the four case studies from the text (insulin pump, patient information system, wilderness weather station, digital learning environment for schools). Describe a scenario relative to your selected case study that illustrates the XP component you selected.Your analysis should be at least 350 but not more than 600 words.