After the sneezer is praised (by others saying "Yarhamuk Allah"), must the sneezer respond to each praiser individually, or is a single response sufficient for everyone, using the plural form or the singular intending each one?

If a Muslim sneezes and praises Allah, and is responded to by someone who heard him, it is sunnah for him to reply to them with the words: "May Allah guide you and rectify your affairs" (yahdīkum Allāhu wa yusliḥu bālakum) or "May Allah forgive us and you" (yaghfiru Allāhu lanā wa lakum), using the plural form, even if the person responding is only one. The reason for the plural form is that the angels also respond to the sneezer, so it is as if they, along with the human responder, form a group. It is also permissible for him to say: "May Allah guide you and rectify your affairs" (yahdīka Allāhu wa yusliḥu bālaka), intending all who responded to him, for deeds are by intentions.