The complex with highest magnitude of crystal field splitting energy $\left(\Delta_{0}\right)$ is :
$\left[\mathrm{Fe}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$
$\left[\mathrm{Mn}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$
$\left[\mathrm{Cr}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$
$\left[\mathrm{Ti}\left(\mathrm{OH}_{2}\right)_{6}\right]^{3+}$
