Dealer: West

Vuln: E/W

The most obvious lead is to lead the suit that you and partner bid but will that lead to 4 defensive tricks? You have hopefully one Spade winners and you are going to need to find partner with three more. If partner has three tricks surely he would have now Doubled there 4♣ bid. So you are going to have to think again. If partner has the heart Ace or control of the trump suit maybe you can get a Heat ruff before declarer has had a chance to draw all the trumps.

So with this in mind, you should lead the ♥3. Declarer wins with the Ace and now plays a club and partner is able to win that trick with the trump Ace and give you your first ruff by playing back a Heart . You now underlead your Spade over to partner's Ace and partner is able to give you a second ruff and you have now defeated the contract taking 2 Black Aces and two Heart ruffs for a well defended and well thought out hand.

Notice the Power of the weak 2 keeping North South out of a very nice 4♥ contract. Without the weak two opener it North South might find the Heart contract - "maybe"  Maybe South might have doubled 3♠ As they say in Spanish Quizas Quizas Quizas   Perhaps Perhaps  Perhaps