Covariant return types

You have the following hierarchy of classes:

class A { }

class B extends A { }

class C extends B { }

class D extends B { }

class E extends A { }

class F extends B { }

There are two classes which return instances of some of the classes above.

class BaseReturner {
    
    public XXX get() {
        return new C();
    }
}

class CReturner extends BaseReturner {
    
    @Override
    public C get() {
        return new C();
    }
}

class FReturner extends BaseReturner {
    
    @Override
    public F get() {
        return new F();
    }
}

What class can be written instead of XXX to compile the code above? Select all that apply.