What do constructors typically initialize in a newly created object?

Constructors play a crucial role in object-oriented programming, as they are special methods called when an object is instantiated. Their primary purpose is to initialize the attributes of a newly created object, ensuring that it starts with a defined state.

When an object is created, the constructor triggers the setup of instance variables (or attributes), which hold the data pertinent to that specific object. For instance, in a class representing a 'Car', a constructor would typically initialize attributes like 'color', 'make', 'model', and 'year'. This initialization is vital because it allows instances of the class to function correctly right from their creation.

In contrast to initializing object attributes, the other options do not represent the primary responsibilities of a constructor. Class methods are part of the class structure but aren't directly initialized by the constructor. The program’s main function is not related to object instantiation; rather, it serves as the entry point for program execution. Algorithms used within the class might be defined as methods but are not initialized by the constructor in the same way attributes are.

Hence, the focus of a constructor is unequivocally on the initialization of object attributes, setting the groundwork for the object's data and behavior as it begins its lifecycle within the program.