Which of the structure is incorrcet? 1 : struct aa { int a; float b; }; 2 : struct aa { int a; float b; struct aa var; }; 3 : struct aa { int a; float b; struct aa *var; };

• 1 :

  struct aa
  { int a; float b;
  };

• 2 :

  struct aa
  { int a; float b; struct aa var;
  };

• 3 :

  struct aa
  { int a; float b; struct aa *var;
  };

• A. 1
• B. 2
• C. 3
• D. 1, 2, 3