El óxido más conocido es el óxido de hierro ¿describe qué características tiene tales como su olor, textura y color? ¿Por qué crees que se forma este óxido en ciertas superficies?

i think its b

explanation:

when it is at an intermediate population density

fumikage isn't really a bird, and tsuyu does have teeth. tsuyu has a transformation quirk which still allows her to be partially human. otherwise we'd have a large frog running around. fumikage has teeth because again, he isn't a bird. his head was a quirk mixture if i'm correct.