不定项选择题 Given the uncompleted code of a class:
   class Person  {
   String name,  department;
   int age;
   public Person(String n) { name = n;  }
   public Person(String n,  int a){ name = n; age = a;  }
   public Person(String n,  String d,  int a)  {
   // doing the same as two arguments version of constructor
   // including assignment name=n,age=a
   department = d;
   }
   }
   Which expression can be added at the "doing the same as…" part of the constructor?
   A．Person(n，a)；                       B．this(Person(n，a))；
   C．this(n，a)；                         D．this(name，age)；