Question: Yvonne Mounsey, the South African-American ballet dancer was known for the important roles she created in the works of which choreographer who co-founded the New York City Ballet?
Sentence (from "Yvonne Mounsey"): Described as "a dancer of glamour, wit, and striking presence," she spent ten years with the New York City Ballet (1949-1959), where she created important roles in the works of George Balanchine and Jerome Robbins.
Relevant evidence: Yes