Beware of the 'Empty Cannon' move by Red when the Black Horse is isolated at 6th Rank 4. The Red Chariot at 5th Rank 4 is setting up a 'Straight Chariot' trap targeting the Black Pawn at 6th Rank 3. Which move by Red will force the Black General at 6th Rank 9 to 'Retreat in Disgrace'?