How is graffiti typically used as an art form?

Graffiti is an art form because people put their entire soul into the art they are making even is sometimes its on someone elses canvis the most likely reason graffiti artists use buildings is because either they cant get their art into a museum themselves or maybe its because the budget calls for it. either way graffiti is definatly an art form and its used to express onesself mostlikely

White flour this don't make sense

Iwant to say it might be a or c my friend