The effect of the Kansas-Nebraska Act was that the violence in Kansas and Nebraska caused by the issues surrounding enslavement ended.
The Kansas-Nebraska Act is a legislation that allowed the people in Kansas and Nebraska to decide if they wanted slavery or not
The legislation stated that people in each territory would vote on whether they wanted to allow slavery or not.
Hence, the violence in Kansas and Nebraska caused by the issues surrounding enslavement ended.
Therefore, the Option A is correct
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