in java

Is the following class legal? Please explain why it is legal or not legal in addition to the answer

Choose the correct reason why or why not

abstract class Cousins

{

abstract void a();

public void b()

{

a();

System.out.println("b"); }

}

a) Yes- we'll have an a() method once we have an object from a conrete child class

b) no- concrete methods cant call abastract methods from the same class

c) no- though a chid class must provide a(), its signature might change.

d) no-the child class might also be abstract