The part of a removable denture that forms a structure of metal struts that engages and unites the metal casting with the resin forming the denture base is called.. Denture base connecter

The part of a removable denture that forms a structure of metal struts that engages and unites the metal casting with the resin forming the denture base is called:
1. Minor connecter.
2. Major connecter.
3. Denture base connecter.***
4. Retainer.