Define abstraction in the context of OOP.

Abstraction in object-oriented programming (OOP) is a fundamental concept that allows programmers to focus on the essential features of an object while ignoring the complex details. By using abstraction, complex systems can be simplified, allowing developers to interact with objects through a simplified interface that reveals only the necessary attributes and operations.

This means that the underlying implementation details of how an object works are hidden from the user, which makes the code easier to manage and reduce the potential for errors. For instance, when you use a car object, you might interact with methods like "start" or "drive" without needing to understand the intricate mechanics of the engine or the electrical systems. This separation of the essential characteristics from the complexities enables better organization and maintenance of code.

In the context of the other options, the first choice incorrectly associates abstraction with a lack of modular design, which is not a characteristic of abstraction. The second option defines a different process related to file execution rather than abstraction itself. Lastly, while the fourth option touches upon accessibility, it does not capture the essence of what abstraction entails, which is about exposing only the necessary parts while concealing the complex reality behind them. Hence, the correct answer effectively captures the essence of abstraction in OOP.