Final answer:
The oldest existing form of Japanese theater combining dance, drama, and music, targeting upper-class audiences such as the samurai, is Noh theatre, which is known for its slow and subtle movements.
Step-by-step explanation:
The oldest form of existing theater in Japan that combines dance, drama, and music and became aimed at the upper classes is B. Noh.
Noh theatre is a sophisticated performance art practiced in Japan since the 14th century. Catering primarily to the samurai and other elite social classes, Noh is characterized by its slow, deliberate movements and an emphasis on minimalism and tradition. This theatrical form integrates elements of dance, drama, and music to create a unique storytelling experience. Known for its masked performances, Noh involves actors who train rigorously to express emotions and stories through subtle gestures and postures. It is distinct from Kabuki, which originated later in the 17th century and is more flamboyant, often performed by male actors in heavily stylized makeup and extravagant costumes. Noh's enduring appeal and deep historical roots make it not only a significant cultural heritage of Japan but also an exemplar of classical Japanese aesthetics in performance arts.