Final answer:
The best description of interethnic marriage data in the United States is that one in seven current marriages is counted as interethnic, reflecting the sociological evidence of increasing acceptance and prevalence of such unions.
Step-by-step explanation:
The data on interethnic marriage in the United States is best described by the statement that one in seven current marriages is officially counted as interethnic. This statistic can be inferred from available sociological research on marriage patterns in the U.S. While the information provided does not directly state the percentage of interethnic marriages, we can deduce that interethnic relationships are increasingly common and accepted in many communities, as evidenced by the high percentage of people who would welcome individuals of different ethnic backgrounds into their families. Moreover, given the diversity of family structures and the evolving nature of societal norms, it is reasonable to infer that interethnic marriages constitute a significant portion of current marriages.