Final answer:
Encapsulation in Object-Oriented Programming ensures that only an object's methods can directly access and alter its data, protecting the object's integrity by limiting external interference.
Step-by-step explanation:
What results in only the object's methods being able to directly access and make changes to the object's data is Encapsulation. Encapsulation is one of the four fundamental Object-Oriented Programming (OOP) concepts. The purpose of encapsulation is to restrict access to the internal state of an object and to protect the object's integrity by preventing external interference and misuse. Essentially, encapsulation makes the object's data private, and can only be accessed or modified through its own methods, which are the public interface of the object.
In contrast, Inheritance is a mechanism where a new class inherits properties and behaviors from another class. Polymorphism refers to the ability of different objects to respond in their own way to the same message (or method call). Lastly, Abstraction focuses on exposing only relevant high-level functionality and hiding the implementation details from the user.