Let A be the centre of the circle x2+y2−2x−4y−20=0. Let B(1,7) and D(4,−2) be two points on the circle such that tangents at B and D meet at C. The area of the quadrilateral ABCD is
(A) 150 sq. units
(B) 50sq. units
(C) 75sq. units
(D) 70sq. units
Ans(C)