A ladder \(20 \mathrm{ft}\) long leans against a vertical wall. The top end slides downwards at the rate of \(2 \mathrm{ft}\) per second. The rate at which the lower end moves on a horizontal floor when it is \(12 \mathrm{ft}\) from the wall is
(A) \(\frac{8}{3}\)
(B) \(\frac{6}{5}\)
(C) \(\frac{3}{2}\)
(D) \(\frac{17}{4}\)
Ans(A)
