I'm going to say...
1) Beef Ribs - very bare ribs. I would not feed those!
2) Knuckle bones with part of the femur attached. I would feed these, but supervise dilligently.
3) Knuckle bones? It would help if they were out of the bag. They look meaty and fatty, though... so I would feed them, and take them away when the tissue was gone.
4) Ew. D;