Final answer:
The original inhabitants of Britain were not known as administrators, builders, and conquerors; this description better suits the Romans. After the Romans left, the Anglo-Saxon invaders were not administrators by typical standards.
Step-by-step explanation:
The original inhabitants of Britain before the Anglo-Saxon period were indeed under Roman control and can be considered part of an administrative system, although the term administrators would be more accurately applied to the Roman ruling class rather than the indigenous Celtic tribes. After the Romans left around 400 CE, Britain was no longer an organized province with builders and conquerors in the Roman sense. The assertion that the original inhabitants of Britain were known for being administrators, builders, and conquerors is false because that description better fits the Romans who occupied Britain rather than the Celtic Britons themselves. Also, the Anglo-Saxon invaders who followed were not so much administrators but were tribal warriors who later established their own systems of governance.