Read the excerpt from "Georgia O'Keeffe: Modernist Pioneer."

In 1917, Stieglitz presented a solo show of O’Keeffe’s work. After a repeat success, more exhibits followed. In the summer of 1918, she left her teaching job and moved to New York to paint full time. There she became a member of a small circle of modernists who were also backed by Stieglitz. She married him six years later in 1924, and their shared vision led to a life of support for each other’s work. Over the next twenty-two years, the two of them enjoyed one of the best partnerships in art history.

Which descriptive detail best conveys the author's viewpoint that Stieglitz and O'Keeffe had a very strong marriage?

"backed by Stieglitz"
"repeat success"
"a small circle"
"best partnerships"