Most banks now have customer relationship software which, when a customer contacts the bank, tells the service representative what types of accounts, loans, and credit cards the customer currently has. Service representatives use this information to sell some of the other services the bank currently offers to these customers. This is a __________ growth strategy.
a. product proliferation
b. market development
c. market penetration
d. diversification
e. product development
Answer: c. market penetration