Which organization is responsible for funding public arts in the subway?

MTA Arts for Transit is the organization specifically tasked with funding and managing public arts projects within the subway system in New York City. This initiative was created to enhance the experience of riders by integrating art into the transit environment. The program funds various artworks, including murals, mosaics, and installations, aiming to make subway stations more visually appealing and culturally enriching for the millions who use the system daily.

Other organizations mentioned, such as the New York Arts Council, focus on broader arts funding initiatives and do not have a dedicated role within the subway system. The Metropolitan Museum of Art and the New York Public Library, while significant cultural institutions in the city, are not directly involved in the public arts program for transportation infrastructure. Thus, MTA Arts for Transit is the correct answer, as its mission directly aligns with the funding and promotion of art in the subway.