The correct answer is option 'C', the RAD (Rapid Application Development) model.

RAD is a high-speed adaptation of the linear sequential model, where rapid development is achieved by using component-based construction. This model was developed to address the limitations of the waterfall model, which follows a sequential approach and does not allow for changes once a phase is completed.

RAD model, on the other hand, focuses on iterative development and the use of pre-built components. It emphasizes active user involvement and collaboration throughout the development process.

Below are the key characteristics of the RAD model:

1. Rapid Development: The RAD model aims to deliver software quickly by focusing on the shortest possible development time. This is achieved by using pre-built components and prototypes that can be quickly assembled.

2. Component-Based Construction: RAD emphasizes the use of pre-built components, which can be easily integrated to create the final software product. This approach allows for greater reusability and reduces the time required for development.

3. Iterative Development: The RAD model follows an iterative approach, where the development process is divided into multiple iterations or prototypes. Each prototype is developed, reviewed, and refined by the stakeholders before moving on to the next iteration. This allows for early feedback and ensures that the final product meets the user's requirements.

4. Active User Involvement: RAD places a strong emphasis on active user involvement throughout the development process. Users are actively engaged in the requirements gathering, prototyping, and testing phases. This ensures that the software meets the user's expectations and reduces the risk of miscommunication.

5. Collaborative Approach: RAD promotes collaboration among developers, users, and other stakeholders. This collaborative approach helps in identifying and resolving issues quickly, ensuring a smooth development process.

Overall, the RAD model is a high-speed adaptation of the linear sequential model, which focuses on rapid development through component-based construction, iterative development, active user involvement, and collaboration. It is particularly useful in projects where time-to-market is critical and requirements are subject to change.