Final answer:
Claude Levi-Strauss used the cultural practices of Inner Asian Steppe peoples and the cultural choices of chieftains and elite families to back up his kinship ideas on marriage.
Step-by-step explanation:
Claude Levi-Strauss used various sources to back up his kinship ideas on marriage. One of the sources he drew upon was the cultural practices of Inner Asian Steppe peoples, who commonly practiced customs such as the levirate, in which a young male marries his elder brother's widow. These practices were also adopted by some early Korean ruling families.
In addition, Levi-Strauss referred to the cultural choices and options available to chieftains and elite families in different regions. He highlighted that the decision on whether to emulate the marriage customs of Chinese, Japanese, or other neighboring cultures presented different possibilities and cultural choices for these groups.