Let \(A\) be the centre of the circle \(x^{2}+y^{2}-2 x-4 y-20=0 .\) 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 \(A B C D\) is
(A) 150 sq. units
(B) \(50 \mathrm{sq}\). units
(C) \(75 \mathrm{sq}\). units
(D) \(70 \mathrm{sq}\). units
Ans(C)
