Final answer:
The correct option is b. The Normans and Anglo-Saxons brought feudalism and castles to their cultural fusion, which were critical components in the medieval societal structure.
Step-by-step explanation:
The Normans (Northmen from Normandy) and the Anglo-Saxons contributed significant cultural and structural advancements to the society they formed after the Norman Conquest of England in 1066.
One of the key contributions of the Normans was the introduction of feudalism, a hierarchical system of land ownership and responsibilities, which became a fundamental aspect of medieval society. Alongside feudalism, the Normans also introduced the concept of castles, which served as fortified structures for defense as well as symbols of Norman power and authority.