Final answer:
The correct relationship between the drawee bank and its customer is that the drawee bank is the customer's debtor upon opening a checking account and acts as an agent during the collection of checks.
Step-by-step explanation:
Regarding the question about the relationship between the drawee bank and its customer, option c is true: The drawee bank becomes the customer's debtor at the time of opening a checking account and agent while collecting checks. When customers deposit money into a bank account, be it a checking account, savings account, or a certificate of deposit, the bank considers these deposits as its liabilities. Essentially, the bank owes this money back to the customer upon their request to withdraw it. Thus, the bank is a debtor to the customer because it has an obligation to return the funds.