While slave codes were in effect,
enslaved people’s activities were not restricted.
enslaved people could enter in legal contracts.
enslaved people could not be legally punished.
enslaved people’s activities were restricted.

I believe the answer is: enslaved people’s activities were restricted.

Slave codes dictate a list of activities that the slaves are banned to do in order to give the slave owners with absolute power over their salves. The codes were designed in a way to destroy's the slaves' will to run away or conducting a rebellion toward the owners.

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.

d. china

good luck

d is the best choice