Which of the following code snippets is correct?

Which of the following code snippets is correct? (Choose 2)

a)

interface Drawable {

abstract function draw();

}

b)

interface Point {

function getX();

function getY();

}

c)

interface Line extends Point {

function getX2();

function getY2();

}

d)

interface Circle implements Point {

function getRadius();

}