Covariant return types

You have the following class hierarchy:

class A { }

class B extends A { }

class C extends B { }

Which methods are overridden correctly according to the covariant return type principle?

class SuperClass {
    
    public A method1() {
        return new A();
    }
    
    public A method2() {
        return new A();
    }
    
    public C method3() {
        return new C();
    }
    
    public SuperClass getInstance() {
        return new SuperClass();
    }

    public long method4() {
        return 0L;
    }
}

class SubClass extends SuperClass {
    
    @Override
    public B method1() {
        return new B();
    }
    
    @Override
    public C method2() {
        return new C();
    }
    
    @Override
    public B method3() {
        return new B();
    }

    @Override
    public SubClass getInstance() {
        return new SubClass();
    }

    @Override
    public int method4() {
        return 0;
    }
}