Answer: the double-ace, not the dime

Lead the double-ace.

Aces are trump. The double-ace is the highest ace. The six-ace is a good trump and it is not the boss. The ace-blank is a little one. None of that is the trap.

The trap is the six-four and the double-five. Ten points each, and neither one is an ace. Lead either dime and a player who is out of that suit can put an ace on it. You bid 30. You cannot stand to donate ten on the opening lead.

Walk the double-ace. You find out who follows aces and who is already out. The six-ace is still in your hand for later. The dimes can wait until trump has been pulled, or until someone else has to lead the suit they live in.

Same habit as the sixes hand from Saturday. Boss trump first. Count when it is safer. The suit changed. The idea did not.