The equation of the curve satisfying the differential equation `y_2(x^2+1)=2x y_1` passing through the point (0,1) and having slope of tangent at `x=0` as 3 (where `y_2` and `y_1` represent 2nd and 1st order derivative), then (a)` y=f( x)` is a strictly increasing function (b)` y=f( x )` is a non-monotonic function (c)` y=f( x) )` has a three distinct real roots (d)`y=f( x)` has only one negative root.