Which of the following is a duty of the customer to the bank?

The duty of the customer to the bank primarily involves safeguarding their own account and financial transactions to prevent fraud, which is why drawing up payments carefully is crucial. When customers take the responsibility to ensure their transactions are accurately recorded and are cautious about the information they provide, they help maintain the integrity of their accounts and reduce the likelihood of fraud. This vigilance not only protects the customer's money but also assists the bank in maintaining security and trust in their systems.

In contrast, setting interest rates, processing loan applications, and managing investment portfolios are responsibilities that typically lie with the bank or financial institution rather than the customer. Interest rates are determined based on various economic factors and policies set by the bank. Loan applications are reviewed and processed by bank staff who assess the creditworthiness of applicants. Similarly, investment portfolio management is a professional service that financial advisors or portfolio managers offer to clients and requires specialized knowledge and expertise beyond the average customer's role.