Which of the following factors drive the need for data warehousing?
a. informational data must be kept together with operational data.
b. reduce virus and trojan horse threats.
c. data warehouses generally have better security.
d. businesses need an integrated view of company information.

A.Informational data must be kept together with operational data.

Explanation:

The data warehousing is an important system of business intelligence that is designed to integrate data into the one single place and is then uploaded from the operational systems such as marketing and sales, and has to pass through the data cleansing and depends on the use of the ETL tools to store the data that is transformed.  It has certain benefits like the Integrate data from multiple sources, mitigate the problem of the database isolation, improved data quality, and make the decision support queries easier to handle.