If A is a 3 by 3 non-singular matrix such that AA^T = A^TA and B = A^(-1)AT,then BB^T is

Q. If A is a 3 by 3 non-singular matrix such that AA^T = A^TA and B = A^(-1)AT,then BB^T is

(A)I+B    (B) I      (c) A+B          (D) AB