Can an object be referenced by variables of several different data types? What is the type or types of the variable(s) that can reference the object created in the following statement? (The...

Can an object be referenced by variables of several different data types?

What is the type or types of the variable(s) that can reference the

object created in the following statement? (The definition of the class

Undergraduate is given in listing 8.4.)

Undergraduate ug = new Undergraduate();