2024/09/16 DPA: "Which Utensil Is Best?"

White to move:

White must find a way to stop promotion.

Assuming you didn't read the title, the only practical way is to win the Queen and the only way to do this is by trapping or skewering it.  Since it's in the open, trapping it is no possible.  So it must be a skewer.

1. Qh7+

What might make this challenging to find is that it's a LQM [Lateral Queen Move] which also seemingly moves *away* from the action [same idea with a BQM <Backward Queen Move>].

The clue that a skewer could be successful is the spacing between the King and the other piece:  if there are 1 or more squares [in this case, there is 1], the King cannot protect the other piece.  If the King is directly adjacent [0 squares of space], the King has a chance to protect [but there's no guarantee:  those other squares could be blocked/controlled so the skewer might still work].