The correct answer is A) to ensure individual freedoms.
The 9th amendment essentially states that any right not given specifically to the government is retained by the people. The implementation of this amendment was rooted in the fears of American citizens who worried about a tyrannical central government that would take away the rights of citizens. This paranoia about a strong central government really originated due to America's relationship with the British during the late 18th century.
This is why when America became independent, they tried to create a government structure in which the central government was extremely limited in its scope.
People thought slavery would end because revolutionary idealism went against it and many leaders spoke about freeing their slaves. Others thought that economics would kill it because it was unprofitable. The invention of the cotton gin saved slavery.
The increasing demand for slave labor and the banning of slave importation by Congress in 1808 led to an increase in the domestic slave trade. Planters’ wives were not allowed any contact with the slaves.