Ellen Longbow is the chief financial officer (CFO) at a startup e-commerce firm that sells products popular with college students. She has asked you to do some Internet research on three competing companies that permit credit-card purchases at their e-commerce sites. Create a table (or spreadsheet) that summarizes how each site handles the following issues: (a) what information does each site require before permitting you to use a credit card? (b) What steps must you go through to complete a transaction? (c) What features do they incorporate to facilitate overcoming the limits of security, merchant risk, cost, etc.? (d) How do they authenticate cardholder identities?