Yes You Can! is an after-school program for 12- to 18-year-olds that allows students to create and implement different community projects. It is run by a group of retired business professionals and student volunteers during the school year. The majority of funding comes from the provincial government. The board of directors is composed of teachers, parents, and a business professional. Recently, one of the board members learned that the implementation of performance measures is a not-for-profit best practice. There are four categories of measures to consider: financial measures, internal business measures, learning and growth measures, and social impact measures. Which of the following would be a good social impact measure? Question 14 options: a) Cost per student enrolled b) The number of training sessions offered to volunteers c) The number of hours spent on community projects d) Number of returning volunteers