[" 19.The solution of the differential equation "xdy+ydx-sqrt(1-x^(2)y^(2))dx=0" is "],[[" (A) "sin^(-1)xy=C-x," (B) "xy=sin(x+C)],[" (C) "log(1-x^(2)y^(2))=x+C," (D) "y=x sin x+C]]