What does object-oriented programming primarily focus on?

Object-oriented programming (OOP) primarily focuses on data and code as objects. This paradigm is built around the concept of encapsulating data and behaviors together into singular entities known as objects. Each object can represent real-world entities, including their attributes (data) and methods (functions) that operate on that data. This structure allows for more modular, reusable, and manageable code, as objects can interact with one another while hiding their internal state and requiring interaction through defined interfaces.

In contrast, the other options do not align with the core principles of OOP. For instance, while functions and procedures are essential in procedural programming, they do not encapsulate data and behavior like objects do. Linear programming techniques pertain to optimization and are not about managing objects or their interactions. Database management systems focus on data storage and manipulation, which are distinct from the encapsulation and interaction patterns that define OOP. Thus, the essence of object-oriented programming lies in treating data as integral components of the structure through objects, a fundamental feature that enhances software development processes.