Which of the following is a key feature of object-oriented programming?

A key feature of object-oriented programming is its emphasis on data abstraction and modularity. This programming paradigm is designed around the concept of "objects," which encapsulate data and the methods that operate on that data. By emphasizing data abstraction, object-oriented programming allows developers to focus on the essential qualities of an object and hide the complex implementation details. This leads to more manageable and reusable code.

Modularity is also a central concept in this paradigm, as it encourages the organization of code into smaller, independent units or modules (i.e., classes). This modularity promotes an easier understanding of software structure and enhances collaboration among developers since different modules can be developed and tested independently before integration.

In contrast, the other choices focus on different aspects of programming that do not align with the principles of object-oriented design. Function-oriented structures emphasize a procedural approach, while the use of charts and diagrams is not specific to object-oriented programming. Sequential programming processes also do not reflect the fundamental concepts of encapsulation or modularity that are central to object-oriented practices.