For the following code, which statement is not true? public class Sphere { private double radius; public double x; private double y private double z; } Select one: O a. radius is not available to code written outside the Sphere class. b. radius, x, y, and z are called members of the Sphere class. c. z is available to code that is written outside the Sphere class, Od x is available to code that is written outside the Sphere class