Most amphibians breathe with gills as larvae and with lungs as adults.
All frogs are amphibians.
Frogs  breathe with gills as larvae and with lungs as adults.
An example of organisms that breathes with gills as larvae and with lungs as adults are
a) mollusk
b) salmon
c) a fish
d) harmful
e) reptile
f) amoeba
g) frogs
h) arachnid