Final answer:
Bartolomé de Las Casas sought to protect Native Americans by asking the king of Spain to outlaw their enslavement, leading to the New Laws of 1542, which were aimed at curbing abuses but had limited enforcement.
Step-by-step explanation:
Bartolomé de Las Casas attempted to help Native Americans by c) asking the king of Spain to enact laws prohibiting their enslavement. He was an advocate for the rights of Indigenous peoples in the Americas and protested against the Spanish colonists' harsh treatment and enslavement of Native Americans. Las Casas is best known for his role in the passage of the New Laws of 1542, which aimed to protect the natives from the most brutal forms of exploitation, although the effective enforcement of these laws was limited and they were eventually relaxed.