Which of the following is NOT a main stage of the Software Development Lifecycle (SDLC)?

Data Mining is not considered a main stage of the Software Development Lifecycle (SDLC). The SDLC consists of several key phases, including requirements gathering, design, implementation, testing, deployment, and maintenance. Each of these phases is crucial for the successful development and delivery of software products.

In contrast, Data Mining refers to the process of discovering patterns and knowledge from large amounts of data. It is an analytical process that can occur after software has been developed or in parallel to certain software applications, but it does not form a foundational stage of the SDLC itself. The other stages—Testing, Design, and Deployment—are all integral parts of the methodical process that guides the creation and management of software, making them essential to the SDLC framework.