The correct option is A ammonotelic
Nitrogenous wastes can be excreted in the form of ammonia, urea or uric acid. Accordingly, the organisms are categorised into - ammonotelic, ureotelic and uricotelic .
Excretion of ammonia requires a large quantity of water. Thus, most of the aquatic organisms are ammonotelic. Tadpole lives in water unlike an adult frog which lives on land. Hence, tadpoles are ammonotelic while adult frogs are ureotelic.