Q:What is the first name of the person whose video choreography was liberally adapted from for the video "Single Ladies?"  Answer the above question based on the context below:  The music video for "Single Ladies" was shot immediately after that of "If I Were a Boy", but it received less attention during production than the "higher-gloss, higher-profile video" for "If I Were a Boy". Both videos were shot in black-and-white in New York City and were directed by Jake Nava, with whom Beyoncé had worked on previous music videos including "Crazy in Love" and "Beautiful Liar". "Single Ladies" was choreographed by Frank Gatson Jr. and JaQuel Knight, and incorporates J-Setting choreography. The two music videos premiered on MTV's Total Request Live show on October 13, 2008 to reinforce the concept of conflicting personalities. The videos were released to other media outlets on the same date and subsequently included on Beyoncé's remix album with videography, Above and Beyoncé, and the platinum edition of I Am... Sasha Fierce. Beyoncé told Simon Vozick-Levinson of Entertainment Weekly that the inspiration for the video was a 1969 Bob Fosse routine entitled "Mexican Breakfast" seen on The Ed Sullivan Show, which featured Fosse's wife, Gwen Verdon, dancing with two other women. "Mexican Breakfast" had become an Internet viral sensation the previous summer after Unk's "Walk It Out" was dubbed over the original mix. Beyoncé wanted to attempt a similar dance and eventually, the choreography of "Single Ladies" was liberally adapted from "Mexican Breakfast": I saw a video on YouTube. [The dancers] had a plain background and it was shot on the crane; it was 360 degrees, they could move around. And I said, 'This is genius.' We kept a lot of the Fosse choreography and added the down-south thing—it's called J-Setting, where one person does something and the next person follows. So it was a strange mixture ... It's like the most urban choreography, mixed with Fosse—very modern and very vintage.
A:
Bob