Fill in the blank with a suitable preposition.
The project was about creating art _______ waste.
The preposition ‘from’ is used to refer to where something is derived or originated from. In the given sentence, the art is created out of waste, thus waste is the point of origin for the art that is created. Therefore option C is correct. On the other hand, ‘to’ is used to refer to the end or the end point of something, which is the opposite of what the sentence attempts to convey. Art is not created so that we can waste it. Therefore option A is incorrect. ‘For’ is a preposition of reason that denotes who/what is meant to have or use something. The art is not created so that we can turn it into waste, rather it is made out of waste. Hence option B is incorrect. The preposition ‘at’ is used to refer to a specific place/spot, which is not apt here since the sentence doesn’t refer to a place. Thus option D is incorrect.