What is true about attributes defined in a constructor?

Attributes defined in a constructor (typically within the __init__ method) are accessible throughout the class as instance variables. When you define attributes in the constructor with self.attribute_name, they become part of the instance of that class, which means you can access and modify those attributes from any method in the same class.

This allows for encapsulation and maintaining the state of an object over its lifetime. For instance, if a class represents a Student, and an attribute self.name is defined in the constructor, that name can be accessed and changed in any other method of the class, which is essential for the object's behavior and interaction.

In contrast, attributes being unmodifiable (as suggested in the first choice) is incorrect since attributes can be changed after their creation, depending on their definitions. The third choice about attributes being only public does not capture the fact that attributes can also be private or protected by convention. Lastly, the idea that attributes are not stored permanently contradicts the fundamental nature of object-oriented programming, where attributes represent the state of an object for its lifetime unless explicitly deleted.