Final answer:
A drama that seriously addresses human existence and includes moral and ethical dilemmas is characterized as a tragedy, which aligns with the provided definition.
Step-by-step explanation:
A drama that addresses serious questions about mankind's existence and includes moral dilemmas, high stakes, and often a somber ending is best described as a tragedy. The essence of tragedy lies in its ability to delve into the ethical choices of its characters, as seen in classical works like those of Shakespeare and the ancient Greeks, where human error and choice are central themes. Comparatively, a comedy generally presents a lighter tone with a tendency to end on a happier note, a farce focuses on humor through exaggerated and improbable situations, and a melodrama distinguishes clearly between good and evil, often resolving in justice being served. Considering these definitions, the most appropriate answer to the question would be C) Tragedy, which uniquely encapsulates the gravity and seriousness needed to explore the profound aspects of human existence.