To answer this question, let's analyze the given code:

class A {
    public static void main(String[] args) {
        A a = new B();
    }
}

class B extends A {}

In the code, a class A is defined with a main method. Inside the main method, an object a of type A is created using the constructor of class B. Class B is a subclass of A.

Since class B extends class A, it is considered to be a subtype of A. Therefore, it is valid to assign an instance of B to a variable of type A. This is known as polymorphism in Java.

Hence, there are no errors in the given code, and the correct answer is C) No errors.

• Thanks
• Wrong explanation