$TiCl_4 + (C_2H_5)_3Al$ is Zeigler Natta catalyst.
$(C_2H_5)_4Pb$ is an anti-knocking agent.
cis-platin is used as an anti-cancer agent]
$A: \left[ Ni ( en )_{3}\right]^{2+}, B :\left[ Ni \left( NH _{3}\right)_{6}\right]^{2+}, C :\left[ Ni \left( H _{2} O \right)_{6}\right]^{2+}$