Final answer:
The Romans introduced Latin language to Britain, ruled for about 400 years until roughly 400 CE, then their departure led to Anglo-Saxon invasions and settlement, significantly changing the island's cultural landscape.
Step-by-step explanation:
The Romans introduced many aspects of their culture to the island of Britain, but the best answer to the student's question is option a): Latin language, with their rule lasting about 400 years, and the period that followed characterized by Anglo-Saxon invasions. After the Roman legions withdrew around 400 CE, the power vacuum led to the Germanic Anglo-Saxons invading and settling, marking the beginning of English history in a de-Romanized Britain.
Roman influence included the introduction of Latin, which persisted as a language of the educated even after the fall of the Roman political authority traditionally marked at 476 CE. Furthermore, the Romans established infrastructure such as roads and fortifications in Britain. The culture and the Latin language they brought greatly influenced the future linguistic and societal development of the region, with Latin later influencing the languages that developed in the territory.