The maximum quantity of water required per day by a human body is

The volume of the filtrate per day is $X$ liters and the volume of urine released per day is $Y$ liters. It means about $Z$ $\%$ of the filtrate is reabsorbed by the process of reabsorption.

Which one of the following options gives the correct categorization of six animals according to the type of nitrogenous waste they excrete?

Option	Ammonotelic	Ureotelic	Uricotelic
$a$	Pigeon,human	Aquatic amphibia,lizards	Cockroach,frog
$b$	Frog,lizards	Aquatic amphibia,humans	Cockroach,pigeon
$c$	Aquatic amphibia	Frog,human	Pigeon,lizards,cockroach
$d$	Aquatic amphibia	Cockroach,humans	Frog,pigeon,lizards

Which one of the following statements is not correct?

$A$: Birds have metanephric kidneys and no urinary bladder.
$R$: South American Ostrich has a urinary bladder.

The primary function of the kidney is ........ .