Your answer would be "made it legal to keep enslaved people for their entire lives."
The laws that established an official system of slavery in the American colonies stated that it made it legal to keep enslaved people for their entire lives.
Explanation:
The reason why this would be your answer is because the law that allowed people in enslave others allowed them to keep them for the rest of their lives. People that pay for salves wouldn't want to release them, since they payed a lot of money in an auction to get a slave. When a slave is brought to their official owner, they would be with that owner for life  unless the owner puts them up for auction. No law during their time made it illegal for people from keeping slaves for their entire life. Some slaves were slaves for the rest of their lives til they died. A lot of people, slaves, suffered either most of their lives or their whole life because of this law.
Why the other answer choices are wrong:
The answer choice: "children could not be born into slavery" is INCORRECT because whenever a child was born into a mother that was a slave, the child automatically becomes a slave, without any exceptions. There were mothers that were slaves that were pregnant, and gave birth to the child while still being a  slave. Their owners or laws didn't deny them from being pregnant. The child would be a slave at a very young age.
The answer choice: "allowed enslaved people to go free if they had been indentured" is INCORRECT is because slaves worked very hard and brutal labors. Even though they never get breaks and brutally worked everyday, this didn't make them become free. The owners kept them working hard labor, no matter how hard the task was.
The answer choice: "required that a person’s enslavement end after a period of time" is INCORRECT because slavers would be a slave for life. There was no law during their time where slaves only had a certain amount of time to be slaves. As soon as someone becomes a slave, they're a slave for life.
