Which of the following can be an example of a database?

A database is a structured collection of data that is organized and stored in a way that allows for efficient retrieval, management, and manipulation of the data. It can include various types of information and can serve different purposes. All of the provided options are examples of databases:

Option A: An address book containing the contact details of all the suppliers of a company can be considered a database. It stores structured information about suppliers, allowing easy access and management of their contact information.
Option B: A salary sheet containing the salary details of all employees of a company is also an example of a database. It stores data related to employee salaries, which can be organized and manipulated for payroll processing and analysis.
Option C: The records of daily sales transactions of a company represent a database as well. This type of database stores information about sales transactions, which can be used for tracking sales performance and generating reports.
Option D: All of the above options are valid examples of databases. They each involve storing structured data for specific purposes, making them organized collections of information that can be queried, updated, and managed efficiently.

Therefore, the correct option is Option D: All of above.