Joseph Pulitzer is often associated with yellow journalism during the Spanish-American War, as his newspaper, the New York World, engaged in sensationalist coverage at that time. However, the concept of "abandoning" yellow journalism is more complex, as Pulitzer's practices evolved over time. By the early 1900s, he began to emphasize more serious journalism.
Thus, the most appropriate response would be:
After the Spanish-American War
This period marks a significant shift in the nature of journalism that Pulitzer and others adopted, moving towards more responsible reporting.