Final answer:
Medieval romances are characterized by a hero's adventures, poetry or prose, fantastical elements, and a focus on chivalry, but not typically by a realistic plot or tales of an ordinary person.
Step-by-step explanation:
Medieval romances are a distinctive genre of literature that flourished during the Middle Ages, and their key characteristics can help us identify and understand them. Medieval romances often include a hero's adventures, where the protagonist embarks on a journey filled with challenges and quests. The narratives can be written in either poetry or prose, depending on the author's choice and the conventions of the time. Contrary to focusing on commonplace events, these stories typically employ fantastical elements such as magic, mythical creatures, and enchanted lands. Moreover, a significant feature of medieval romances is a focus on chivalry, where the concepts of honor, courtly love, and the knightly code of conduct are central themes.
On the other hand, some possibilities presented in the question don't usually characterize a medieval romance like 'a realistic plot' or 'tales of an ordinary person', as these stories often feature extraordinary characters, settings, and events that go beyond the mundane aspects of life.