Banking analyst: Banks often offer various services to new customers at no charge. But this is not an ideal business practice, since regular, long-term customers, who make up the bulk of the business for most banks, are excluded from these special offers. Which one of the following, if true, most strengthens the banking analyst's argument'? ['Most banks have similar charges for most services and pay similar interest rates on deposits.', 'Banks do best when offering special privileges only to their most loyal customers.', 'Offering services at no charge to all of its current customers would be prohibitively expensive for a bank.', 'Once they have chosen a bank, people tend to remain loyal to that bank.']