Final answer:
The most primitive bony fish belongs to Class Sarcopterygii, within the clade Osteichthyes. This group is characterized by a bony skeleton and includes the lobe-finned fishes.
Step-by-step explanation:
The taxonomic classification for the most primitive bony fish is Class Sarcopterygii, which belongs to the clade Osteichthyes or bony fishes. Bony fishes are characterized by a bony skeleton and are the largest class of vertebrates. Within the bony fishes, the most primitive group is the lobe-finned fishes.