Another day, another task!
Today's challenge is to construct four positions, with White to move and win, such that:
In each position, White's move is to promote to a particular piece, for a position per promotion choice.
Black's next best move is to promote to a piece, and Black promotes to the same piece that White does.
Therefore, White may not promote with check, but Black can
The position must be legal, and FIDE laws of chess apply.
The real challenge is that you must use as few pieces as possible for each position. You must also state both White's and Black's motivation for their promotion.