To solve this question, it is important to understand the concept of constructors in object-oriented programming.

A constructor is a special method within a class that is used to create and initialize objects of that class. It is called automatically when an object of the class is created.

Now, let's go through each option and explain why it is right or wrong:

A. is used to create objects: This option is correct. Constructors are used to create objects of a class. They initialize the object's state and allocate memory for it.

B. must have the same name as the class it is declared within: This option is correct. Constructors must have the same name as the class they are declared within. This is a naming convention that helps identify and associate the constructor with its corresponding class.

C. maybe overloaded: This option is correct. Constructors can be overloaded, which means that a class can have multiple constructors with different parameter lists. Overloading allows for flexibility in creating objects with different initializations.

D. b and c: This option is correct. Both option B and C are correct, as explained above.

E. all of the above: This option is correct. Since options A, B, and C are all correct, option E, which states "all of the above," is the correct answer.

The Answer is: E