Definition: In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].
Input: (CNN) -- U.S. boxing history reveals that it is a sport that has traditionally been the "bluest" of blue-collar athletic endeavors. It has always held out the promise -- despite the odds -- of advancement for young men with the talent and guts to succeed in an often bloody undertaking, beginning with the arrival of the Irish in the mid-19th century, and for African- Americans and the later influx of Jews, Italians and Hispanics, whether U.S.-born, from Mexico or from the Caribbean. Three of the earliest success stories in this history were men of Mexican-American heritage from Los Angeles: Solomon Garcia Smith in the 1880s; Joe Salas, the first Latino to medal in boxing in the Olympics, in 1924; and Bert Colima, Pacific Coast champion in three divisions during the 1920s.Jorge Iber says boxing in U.S. has long been chance for advancement among immigrantsHe says it lets Mexican-Americans show mettle, become source of pride in communitiesTitle IX helped open opportunity to women too; Olympic hopeful Marlen Exparza one exampleIber: For Latinas, especially "new arrivals," a chance in sports helps them join community 
 Question:In recent decades, the playing field has been leveled substantially, in part due to _ -- the 1972 law that increased opportunities for women in high school and college athletics -- and a series of court decisions.

Title IX