Joanna, a member, is a sole proprietor that specializes in data processing system design and installation. To facilitate her work and provide additional service to her clients, Joanna purchases various products for sale to her clients. Joanna takes title to the products and assumes all of the risks of ownership. The profit on the sale of these products to her clients is:

• a) a referral fee
• b) a commission
• c) not allowed
• d) None of the above