Consider the following four statements (A–D) related to the common frog $Rana\ tigrina$, and select the correct option stating which ones are true (T) and which ones are false (F).
Statements:
(A) On dry land it would die due to lack of $O_2$ if its mouth is forcibly kept closed for a few days.
(B) It has four chambered heart.
(C) On dry land it turns uricotelic from ureotelic.
(D) Its life history is carried out in pond water.

(A) is false: the frog does not breathe through its open mouth. On land it respires through the skin (cutaneous), the buccal cavity and the lungs, drawing air in through the nostrils with the mouth kept closed. Keeping the mouth closed therefore does not cut off its oxygen.
(B) is false: the frog's heart is three-chambered, with two atria and one ventricle.
(D) is true: fertilisation is external in water, and the eggs and the tadpole larvae develop in pond water before metamorphosis.
(C): the frog is a ureotelic animal. The answer key of the source treats this statement as true, giving the combination F, F, T, T.
So the option accepted in the key is (A) F, (B) F, (C) T, (D) T.
Note: by NCERT the adult frog stays ureotelic on land, so statement (C) is doubtful and none of the four options fits perfectly; some books give T, F, F, T instead. The key of the source PDF is retained.