This is the same situation as deal four but in a NT contract:
Deal five — 3NT South
Solution–
In this NT contract Partner may have lead away from the A♥️. Don’t stress over it. You should still put in the 10♥️ and save your K♥️ to capture Dummy’s Q♥️. Whether Partner has the A♥️, the J♥️, both, or neither– you should still put in the 10♥️. Think of it this way–do not let Declarer win with the Q♥️.
