Referencing subclass objects

There is a class hierarchy consisting of two classes. Each class has setters and getters to access its protected field from the outside.

class Vehicle {

    protected String regNumber;

    public String getRegNumber() {
        return regNumber;
    }

    public void setRegNumber(String regNumber) {
        this.regNumber = regNumber;
    }
}

class Car extends Vehicle {
    
    protected int numberOfSeats;

    public int getNumberOfSeats() {
        return numberOfSeats;
    }

    public void setNumberOfSeats(int numberOfSeats) {
        this.numberOfSeats = numberOfSeats;
    }
}

Select all incorrect statements.

Vehicle car = new Car(); // (1)

car.setRegNumber("ABC-123"); // (2)
car.setNumberOfSeats(5); // (3)

String regNumber = car.getRegNumber(); // (4)
int seats = car.getNumberOfSeats(); // (5)