Numerous advocates for sustainability have called for increased consumer awareness, arguing that if we acknowledge our ethical responsibility towards the environment, we should avoid products that harm it, either directly or indirectly. However, it is often impractical for consumers to evaluate the environmental consequences of a product, making it difficult for them to intentionally limit their purchases to eco-friendly options. Due to this challenge, there can be no ethical obligation to select products in the manner these advocates suggest, since ___________.

Which one of the following principles best completes the argument?