What is a passbook savings account characterized by?

A passbook savings account is characterized by the use of a physical booklet, which serves as a record for tracking deposits, withdrawals, and accrued interest. This format allows account holders to see their transaction history at a glance and provides a tangible way to monitor their savings. Passbook savings accounts are often associated with traditional banking practices, where transactions are recorded manually in the booklet during bank visits, although many banks now offer electronic alternatives.

The other options do not accurately describe the key features of a passbook savings account. For instance, while some savings accounts may have minimum balance requirements, passbook accounts are typically designed to be more accessible. Moreover, they generally do not offer unlimited transactions, as that feature is more common in checking accounts. Additionally, passbook savings accounts are intended for saving rather than long-term investment opportunities, which are typically associated with other financial products such as stocks or bonds. Therefore, the correct answer highlights the unique aspect of the passbook itself, making it a defining feature of this type of savings account.