Which of the following is not a phase of the Software Development Life Cycle (SDLC)?

In the Software Development Life Cycle (SDLC), the standard phases are:

1. Planning
2. Analysis
3. Design
4. Implementation (Coding)
5. Testing
6. Deployment
7. Maintenance

Looking at your options:
- A. Planning → Yes, part of SDLC.
- B. Analysis → Yes, part of SDLC.
- C. Testing → Yes, part of SDLC.
- D. Maintenance → Yes, part of SDLC.

👉 That means all four listed are valid phases of SDLC.
So the correct answer is: None of the above (because each option is indeed a phase).

Correct Answer: None of these (because all four — Planning, Analysis, Testing, and Maintenance — are actually phases of SDLC).

It seems the answer key in the image has a mistake, because Testing is indeed a valid SDLC phase.