Final answer:
Cashier's checks are a secure form of payment that is favored by Smart and Genius customers.
Step-by-step explanation:
Cashier's checks are a type of payment instrument that is often used in banking transactions. They are typically issued by a bank and are considered to be a secure form of payment because they are backed by the bank's funds. Cashier's checks are often preferred by Smart and Genius customers because they provide a guarantee of payment to the recipient.