参考答案：B

解析：[听力原文]21-25 Once a social taboo, love across the color line is becoming increasingly common. The number of interracial marriages in the U.S. has leaped almost 1,000% since 1967, when a landmark Supreme Court decision, Loving v. Virginia, voided state antimiscegenation laws that forbid unions between the races. Today there are more than 2 million interracial marriages, accounting for about 5% of all U.S. marriages, and almost half a million of them are between blacks and whites. Yet even after the Loving decision, which required the state of Virginia to recognize the marriage between a white man and a black woman, Richard and Mildred Loving, the resistance to mixed nuptials in the South seemed to stay as firm as the reverence some there still have for the Confederate flag. It was only three years ago that Alabama became the last state to drop its unenforceable ban on mixed marriage, and it did so with just a 60%-to-40% vote by residents. Of course, interracial intimacy has been a fact of life in the region since African slaves first arrived in the U.S.—and white slave owners like Thomas Jefferson began sneaking into the slave quarters at night. But what used to be branded clandestine lust has finally evolved into sanctioned love: black-white interracial marriages in Alabama have more than tripled, from 297 in 1990 to 1,000 in 2000, or about 2.5% of the married couples in the state. An additional 1% of Alabama marriages are unions also involving Asians, Latinos and Native Americans.

[分析]： 特定信息的找寻和判断。 根据题干中关键词“a landmark ruling”在原文中找寻与其相关的特定信息部分为原文第一段第二句中“...a landmark Supreme Court decision, Loving v. Virginia”。由此可见，选项b的说法是正确的。[解题关键] 掌握单词的归类。原文中Supreme Court和题干中ruling同属于法律范畴，因此正确答案就在有Supreme Court出现的上下文中。