10th anniversy quest questions.Follow

Ok i have some questions.. there are suppose to be 3 NPC's in POK that give out a trivia quest (has it been confirmed there are 3) and do they all give the same reward... or has anyone done any of them other than vesheen's? I am just curious I read on the forums that you can only do 1 of them and not all 3 and if thats so while I really want the Cloth Cap... I really dont want to waste my only attempt if the other 2 rewards would beneift me better.... ( i dont my spoilers so go ahead and spoil away)