Task: Question Answering
Input (English): Passage: When the painting was unveiled in 1953, most Chinese critics were enthusiastic.  Xu Beihong, the president of CAFA and a pioneer in using realism in oil painting, admired the manner in which the work fulfilled its political mission, but complained that because of the colors, it barely resembled an oil painting.  He and others, though, saw that the painting opened a new chapter in Chinese art development.  Zhu Dan, head of the People's Fine Arts Publishing House, which would reproduce the painting for the masses, argued that it was more a poster than an oil painting.  Other artists stated that Dong's earlier works, such as Kazakh Shepherdess (1947) and Liberation (1949), were better examples of the new national style of art.  Senior Party leaders, though, approved of the painting, as art historian Chang-Tai Hung put it, "seeing it as a testament to the young nation's evolving identity and growing confidence".Soon after the unveiling, Jiang wanted to arrange an exhibition at which government officials, including Mao, could view and publicly endorse the new Chinese art.  He had connections in Mao's inner circle, and Dong and others organized it to be in conjunction with meetings at Zhongnanhai that Mao led. This was, most likely, the only time Mao attended an art exhibition after 1949.  Mao visited the exhibition three times in between meetings and especially liked The Founding of the Nation—the official photograph of the event shows Mao and Zhou Enlai viewing the canvas with Dong.  The chairman stared at the painting for a long time and finally said, "It is a great nation.  It really is a great nation."  Mao also stated that the portrayal of Dong Biwu was particularly well rendered.  As Dong Biwu was in the second row, mostly hidden by the large Zhu De, Mao was most likely joking, but the favorable reaction by the country's leader assured the success of the painting.The Founding of the Nation was hailed as one of the greatest oil paintings ever by a Chinese artist by reviewers in that country, and more than 500,000 reproductions were sold in three months.  Mao's praise helped boost the painting and its painter.  Dong's techniques were seen as bridging the gap between the elitist medium of oil painting and popular art, and as a boost to Jiang's position that realistic art could be politically desirable.  It was reproduced in primary and secondary school textbooks.  The painting appeared on the front page of People's Daily in September 1953, and became an officially approved interior decoration.  One English-language magazine published by the Chinese government for distribution abroad showed a model family in a modern apartment, with a large poster of The Founding of the Nation on the wall.  According to Chang-Tai Hung, the painting "became a celebrated propaganda piece". 
Question: What painting "became a celebrated propaganda piece?"?
Output (English): The Founding of the Nation.