Joy is a new Scrum Master for a development team at a growing tech startup. During her first week, she meets with Lisa, a seasoned developer and Scrum enthusiast in the company. Lisa wants to ensure Joy understands the nuances of the Scrum framework. She poses a question to test her knowledge, "Joy, based on your understanding of Scrum, which event corresponds with the Agile principle that suggests teams should regularly reflect on their efficiency and make necessary adjustments?" a) Continuous improvement b) Lessons learned c) Sprint retrospective d) Sprint review