Concept:A share is a unit of ownership in a company. Selling shares to many people (shareholders) is how a joint stock company raises its capital.Solution:Sole proprietorships get capital from the owner's savings, loans and help from family.Partnerships get capital from the contributions of the partners.Co-operative societies get capital from members' contributions (entrance fees and dues) and loans.Only joint stock companies raise capital by selling shares.Answer:Option C (Joint stock companies)