Question: What stake was held on June 6, 2015 that the American Thoroughbred racehorse Frosted attended?

Context paragraphs:
Dogwood Stable: Dogwood Stable is an American Thoroughbred racehorse partnership founded in 1969 by W. Cothran "Cot" Campbell of Aiken, South Carolina. The pioneers of thoroughbred partnerships, the operation's stated policy is to acquire moderately priced, young horses.  According to their website, since inception, Campbell has introduced more than 1,200 people to the sport of Thoroughbred racing, and Dogwood partnerships have raced more than 70 stakes winners.  In 1990, their colt Summer Squall won the second leg of the U.S. Triple Crown series, the Preakness Stakes.

Reviewer (horse): Reviewer (April 30, 1966 – June 6, 1977) was an American Thoroughbred racehorse best known as the sire of U.S. Racing Hall of Fame filly Ruffian.

The Tin Man (horse): The Tin Man (February 18, 1998 in Kentucky – 2015) was an American thoroughbred racehorse.  The gelding was sired by Affirmed, the Triple Crown of Thoroughbred Racing winner, out of the unplaced Lizzie Rolfe by Tom Rolfe, who was an exceptional racehorse but a better broodmare sire.

Frosted (horse): Frosted (foaled April 18, 2012 in Kentucky) is an American Thoroughbred racehorse.  In 2016, he set a stakes record while winning the Metropolitan Handicap in a "dazzling performance" and followed up with a win in the Whitney Handicap.  Prior to that, despite winning several stakes races, he was best known for finishing behind American Pharoah four times, including a runner-up performance in the 2015 Belmont Stakes.

2015 Belmont Stakes: The 2015 Belmont Stakes (known as the 147th Belmont Stakes presented by DraftKings for sponsorship reasons) was the 147th in the Belmont Stakes series.  The 1+1/2 mi race, known as the "test of the champion" and sometimes called the "final jewel" in thoroughbred horse racing's traditional Triple Crown series, was held on June 6, 2015, three weeks after the Preakness Stakes and five weeks after the Kentucky Derby.  The Belmont Stakes was the 11th race of a 13 race card which included 10 stakes races.Post time for race 11 was 6:52 pm EDT.

Kelso (horse): Kelso (April 4, 1957 – October 16, 1983) was an American thoroughbred race horse considered among the best racehorses in history.  In the list of the top 100 U.S. thoroughbred champions of the 20th Century by The Blood-Horse magazine, Kelso ranks 4th, behind only Man o' War (1st), Secretariat (2nd) and Citation (3rd).  In his long career, Kelso defeated many leading Thorougbred racehorses including Carry Back, Gun Bow, Bald Eagle, Tompion, Never Bend, Beau Purple, Quadrangle, Roman Brother, Crimson Satan, Jaipur, Ridan and Pia Star, as well as other top thoroughbreds, often conceding weight under handicap conditions.  In doing so, Kelso beat more champions and Hall of Fame horses than any other thoroughbred racehorse in the 20th Century.

Cigar (horse): Cigar (April 18, 1990 – October 7, 2014), was an American Thoroughbred racehorse who, in 1995 and 1996, became the first American racehorse racing against top-class competition to win 16 consecutive races since Triple Crown winner Citation did so in 1948 and 1950.  Cigar retired as the leading money earner in Thoroughbred racing history and was later inducted into the National Museum of Racing and Hall of Fame.

Thoroughbred Owners and Breeders Association: The American Thoroughbred Owners and Breeders Association (TOBA) based in Lexington, Kentucky is a trade organization for Thoroughbred racehorse owners and breeders.  Founded in 1961, the TOBA's stated mission is to "improve the economics, integrity and pleasure of the sport on behalf of Thoroughbred owners and breeders."

Crafty Admiral: Crafty Admiral (June 6, 1948 – 1972) was an American Thoroughbred racehorse who was the 1952 American Champion Older Male Horse and Leading broodmare sire in North America in 1978.

Favorite Trick: Favorite Trick (April 20, 1995 – June 6, 2006) was an American Thoroughbred racehorse who in 1997 became the first 2-year-old in twenty-five years to be voted United States Horse of the Year.

Supporting paragraphs: Frosted (horse) 2015 Belmont Stakes
Answer: 2015 Belmont Stakes