It comes from the short plate. Ahead of the flank, behind the foreshank or front leg. If brisket = chest, short plate = diaphragm when comparing beef to people. I knew where it was located and had a hard time verifying it on the internet or finding a picture actually calling it by name.
Cut the BS, i wish you would. This morning I left a county corn/soybean growers meeting where we discussed Ag in the Classroom activities with 3rd graders, Food checkout activities at grocery stores, and how to defend retired land grant academia attacking our farming practices. Your attitude towards this request makes these efforts more challenging. Being honest, blunt, direct, and to the point does not have to be rude and annoying. When you are 2x or 3x your present age, you may begin to understand those generation's approach.