Q) A circle S , whose radius is 1 unit, touches the X axis at point A. The center Q of S lies in the first quadrant . The tangent from the origin O to the circle touches it at T & a point P lies on it such that the triangle  OAP is a right angled triangle at A & its perimeter is 8 unit. then the length of QP is:

(A)2   (B)1/2    (C)4/3   (D)5/3