Final answer:
The first highly decorative braids were seen among the Ancient Greeks, as indicated by historical records detailing the significance of braiding in rituals and customs relating to chastity, such as the six braids adorned by brides and Vestal Virgins.
Step-by-step explanation:
Historically, the first highly decorative braids were seen among various ancient cultures, each using hair styling and adornments to express social, familial, or religious identities. While the reference to 'highly decorative braids' is broad and could potentially include many ancient societies, the provided excerpt from Festus mentioning six braids adorned by both brides and Vestal Virgins suggests a focus on Ancient Greeks. This ancient style was indicative of chastity and was part of the customs observed by brides and dedicated priestesses in Greek culture. Therefore, of the options provided, the Ancient Greeks (D) would be the most fitting answer to the question of where the first highly decorative braids were historically seen.