After auction south to play in 4 hearts. West on lead takes his full holding of 3 hearts out of hañd together and places them face up on table. No specific card selected. West mistakenly thought his partner was declared so no intention of a specific card to play. Does declarer have choice of which card has 'been led' or is it the card which touched table first I.e bottom card. All three were placed on table at same time.