Chooses and activates an NPC dialog option. Results may vary according to the gossip option chosen; may end the gossip (firing a GOSSIP_CLOSED event) and start another interaction (firing a MERCHANT_SHOW, TRAINER_SHOW, TAXIMAP_OPENED, or similar event) or may continue the gossip with new text and new options (firing another GOSSIP_SHOW event).

Calling this function with only the first argument may cause the GOSSIP_CONFIRM event to fire, indicating that the player needs to provide confirmation (or additional information) before the option will be activated. Confirmation is needed for certain options requiring the character to spend (e.g. when activating Dual Talent Specialization); additional information is needed for options such as those used when redeeming a Loot Card code from the WoW trading card game to receive an in-game item. In either case, the confirmation and additional information can be provided (as by the popup dialog in the default UI) by calling this function again with all three arguments.