I believe it is an active voice
This object might be <span>part of a sword</span><span>. </span>We did<span> not </span>think<span> that this much gold was carried by the warrior class but the Staffordshire Hoard has revolutionized our understanding of this period.</span>
I belive it is D because it is a scientific reasons and it gives you data to learn off
Basically, the quote means that this lady has lived a long, tired, and hardworking life. Her soul is at rest because she is satisfied with the life that she lives.