Answer:
Option A
Explanation:
$\frac{dy}{dx}=\frac{x^{2}+y^{2}+1}{2xy}$ ,
$\Rightarrow$ $2xy dy =(x^{2}+1) dx+y^{2}dx$
$\Rightarrow$ $\frac{xd(y^{2})-y^{2}dx}{x^{2}}=\left(\frac{x^{2}+1}{x^{2}}\right)dx$
$\Rightarrow$ $\int d\left(\frac{y^{2}}{x}\right)=\int \left(1+\frac{1}{x^{2}}\right)dx$
$\Rightarrow$ $\frac{y^{2}}{x}=x-\frac{1}{x}+C$
$\Rightarrow$ $y^{2}=(x^{2}-1+Cx)$
where x=1;y=0
$\Rightarrow$ 0=1-1+C
$\Rightarrow$ C=0
$\therefore$ The solution is $x^{2}-y^{2}=1$ i.e, hyperbola