Final answer:
Large enterprises typically use relational databases for transaction processing systems due to their capability to handle complex queries and maintain data integrity efficiently.
Step-by-step explanation:
Transaction processing systems that support a large enterprise typically store data in a relational database. This type of database is designed for handling large amounts of data and complex queries efficiently, while maintaining data integrity and consistent business rules. Relational databases use a structured query language (SQL) for database management, which allows for precise and flexible data retrieval.
Choices like NoSQL databases, Excel sheets, and Access databases might also be used in specific circumstances or within smaller organizations, but for large enterprise applications, a relational database is the standard.