Answer: the answer is A. it promotes the concept of natural rights.
Explanation:
Because popular sovereignty was well supported because it allowed the local citizens of a territory to decide if slavery was to be allowed or illegal. Stephen A. Douglas pushed for popular sovereignty during the 1840's.
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When in doubt, historians should always "<span>C. Search for additional evidence to see which argument it supports" This allows them to reach their own conclusion or confirm the existing one. </span>