<span>A.
Serfs were bound to the land and to the lord of the manor.</span>
“Undeterred by the strict prison rules”“She could tuck . . . messages down a book’s spine.”“[She] made a pinhole above each letter . . . that spelled out her secret message.”<span>“Prisoners could easily respond in the same way.”
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The answer is Not 100%, I chose it and got it wrong. I hope that helps a little.
(C) The Neolithic Revolution took place over thousands of years.