Source: ACBL NABC Atlanta Bulletins
Opening lead: 
K.
Bidding commentary: Strong eight-card suits with less than opening-bid strength (fewer than 10 HCP) should open four, not three! North checks for aces and bids the slam. South must have a play for slam with the North hand as dummy.
Defensive commentary: When holding the K-Q-J of a suit along with a side-suit ace, the K-Q-J suit is the preferred lead. Also, when dummy tables, East knows that West has an ace.
Play commentary: South has two chances to make this contract, not one! He crosses to the closed hand with a trump and leads a spade, not a diamond! If West has the 
A, the diamond finesse is not necessary. After West takes the A, the furnishes a diamond discard. If East has the A, a diamond finesse is still available. In effect, declarer is taking two finesses. If the diamond finesse is taken first and it loses, declarer is down even though West may have the A. Two chances are better than one. When declarer has a singleton facing a king plus another finesse available in a long suit and declarer can afford to lose one trick, lead the singleton suit first. If the ace is well placed, it may mean no finesse will be necessary in the longer suit.