Which method of developing systems is associated with modular and reusable code?

The correct answer is associated with object-oriented analysis, which emphasizes the modularization of code through the use of objects. In object-oriented analysis, systems are developed by modeling real-world entities as "objects" that encapsulate both data and behavior. This approach allows for the creation of reusable components, as classes can be designed with specific functionalities that can be reused in different parts of an application or in different projects altogether.

The modular nature of objects facilitates easier maintenance and scalability of the system. Changes can often be made to one part of the code with minimal impact on others, which enhances flexibility in the development process. This focus on reusability not only saves time and resources but also improves code quality by promoting consistency throughout the system's architecture. In contrast, other methods such as functional programming, procedural programming, and structured analysis do not emphasize modularity and reusability to the same extent, limiting their effectiveness in creating adaptable and maintainable systems.