What would a suitable response be when someone asks if you want to go to the supermarket but you don't need anything?

In this context, the most appropriate response is to say "anything." When someone asks if you want to go to the supermarket and you don’t need anything, responding with "anything" conveys a polite way of saying you are not interested in going. It indicates that while you appreciate the invitation or offer, you don't feel the need to join because you have no specific items to purchase.

Using "anything" suggests openness to the idea but negates the necessity to go since you do not have any particular need. This is a common conversational tactic that makes it clear you’re not dismissing the offer outright; instead, you’re indicating that you are not in a position to accept it at this time.

The other options offer varying degrees of ambiguity or lack of clarity, making them less suitable responses in this social situation.