Final answer:
The information with a 1-to-many relationship with a Customer is 'List of accounts owned,' as a single customer can have multiple accounts. Other options such as family members, last visit, and product usage typically have a 1-to-1 relationship with the customer.
Step-by-step explanation:
The information that has a 1-to-many relationship with a Customer is c. List of accounts owned. This is because a single customer can have multiple accounts, creating a 1-to-many relationship. In contrast, the number of family members, date of last visit to store, and average monthly product usage typically relate to a customer in a 1-to-1 relationship; there's generally one set of family members, one last visit date, and one average usage number per customer.
Understanding these relationships is crucial in fields such as database management and statistics. For example, a marketing manager might be interested in age demographics for tailored campaigns, or a librarian may want to segment data by children and adults to improve library services. Similarly, knowing the number of accounts a customer holds can be valuable information for cross-selling or customer service strategies.