Frédéric Chopin was one of the first composers to incorporate nationalistic elements into his compositions. Joseph Majlis states, "Poland's struggle for freedom from statistics rule aroused the national poet in Poland. ... Examples of musical nationalism abound in the output of the romantic era.
The correct answer is Tchaikovsky, while Chopin was indeed a famous Romantic composer, Tchaikovsky fell into the group labeled the Nationalist Romantic Compsers. The reason for this, is because he included a lot of influence from his home country in his music. Hope this helps (:
