Answer: open-source software framework designed for distributing data-processing over inexpensive computers.
Explanation:
Hadoop refers to the collection of open-source software utilities which are important in facilitating the use of a network of several computers to solve big data.
It provides huge storage for different kinds of data, and the ability to handle concurrent tasks virtually. Therefore, the correct option is "open-source software framework designed for distributing data-processing over inexpensive computers".