Where in the lungs does gas exchange take place?

One of the following animals does not use $tracheae$ as the respiratory organs. This animal is:

An organism $X$ having breathing organs $A$ lives on land. When organism $X$ goes underwater, it cannot survive for a long time unless carrying an oxygen cylinder. On the other hand, the organism $Y$ having breathing organs $B$ always lives in water and if taken out of water, it dies after a short while. A third organism $Z$ having breathing organs $C$ and $D$ which lives on the banks of ponds, lakes, and rivers can survive on land as well as in water equally well.
$(a)$ What could organism $X$ be? Name the breathing organs $A$.
$(b)$ What could organism $Y$ be? Name the breathing organs $B$.
$(c)$ What could organism $Z$ be? Name the breathing organs $C$ and $D$.
$(d)$ Out of $X$, $Y$, and $Z$, which organism is:
$(i)$ Amphibian,
(ii) Aquatic,
(iii) Terrestrial?

From where do aquatic animals and terrestrial animals obtain oxygen for breathing and respiration?

During the respiration of an organism $A$,one molecule of glucose produces two $ATP$ molecules,whereas in the respiration of another organism $B$,one molecule of glucose produces $38$ $ATP$ molecules.
$(a)$ Which organism is undergoing aerobic respiration?
$(b)$ Which organism is undergoing anaerobic respiration?
$(c)$ Which type of organism,$A$ or $B$,can convert glucose into alcohol?
$(d)$ Name one organism which behaves like $A$.
$(e)$ Name two organisms which behave like $B$.

$(i)$ Under normal conditions, what is the rate of breathing per minute for an adult? (ii) Why does the rate of breathing increase significantly during vigorous exercise?