In a food chain consisting of snake, insect, grass and frog, assign an appropriate trophic level to frog.

$\mathrm{Phytoplankton}\to \mathrm{Zooplankton}\to \mathrm{Fish}\to \mathrm{Fish} \mathrm{eating} \mathrm{bird}$.
In this food chain which organisms will have (i) Maximum available energy, (ii) Maximum concentration of pesticides.