Final answer:
The Anglo-Saxons began invading Britain after the Roman withdrawal around 410 AD, with Germanic tribes settling in the region following the departure of Roman legions. Thus, the correct answer to when the Anglo-Saxon invaded the Romans is A. 410 AD.
Step-by-step explanation:
Anglo-Saxon Invasion and Roman Withdrawal
The Anglo-Saxon invasion of Roman Britain did not occur in a singular year; rather, it was a process that began after the Roman legions withdrew from Britain to protect the Roman heartland. By about 400 CE, the Romans had abandoned Britain, and this became more pronounced when the entire army of Britain left in 407 CE. The Germanic Anglo-Saxons, originating from regions that are now northern Germany and Denmark, began to invade, raid, and settle in England during the fifth century CE.
In historical terms, the most accurate response to the question of when the Anglo-Saxons invaded Romans in Britain would be in the period after the Roman withdrawal around 410 AD, as there is no evidence suggesting that Anglo-Saxons invaded during the actual Roman occupation of Britain. Therefore, the correct answer to the student's question is A. 410 AD.