If \( \cos^{-1}\!\left(\dfrac{y}{2}\right)=\log_{e}\!\left(\dfrac{x}{5}\right)^{5},\ |y|<2 \), then:
\( x^2 y'' + x y' - 25y = 0 \)
\( x^2 y'' - x y' - 25y = 0 \)
\( x^2 y'' - x y' + 25y = 0 \)
\( x^2 y'' + x y' + 25y = 0 \)
