Let \( x = x(y) \) be the solution of the differential equation \( 2 y e^{x / y^{2}} \, dx + \left( y^{2} - 4 x e^{x / y^{2}} \right) dy = 0 \) such that \( x(1) = 0 \). Then, \( x(e) \) is equal to:
\( e \ \log_{e}(2) \)
\( -e \ \log_{e}(2) \)
\( e^{2} \ \log_{e}(2) \)
\( -e^{2} \ \log_{e}(2) \)