Final answer:
The term referring to the past era in which medieval knights jousted is 'yore' (Option b). This term is commonly associated with the Middle Ages, a historical period that spanned from the 5th to the 15th century in Europe.
Step-by-step explanation:
The term that refers to time past or long ago, during which medieval knights jousted, is b) Yore. This term is often used to describe the days of knights and chivalry in the Middle Ages, a period in European history that lasted from the 5th until the 15th centuries.
During the Middle Ages, particularly in the Early Middle Ages, the social and military structures were significantly influenced by the practices of knights and feudalism. Over time, however, the nature of warfare evolved, especially during events like the Hundred Years' War, which saw a shift from cavalry-focused armies to professional standing armies. Nonetheless, the times when knights of yore roamed the land, participating in jousts and other chivalrous deeds, remain a subject of fascination and romanticization in history.