Final answer:
Tragedy is the branch of drama that treats serious and dignified sorrowful or terrible events caused by a heroic individual. It involves ethical choices, high stakes, and often ends in the protagonist's downfall.
Step-by-step explanation:
The branch of drama that treats in a serious and dignified style the sorrowful or terrible events encountered or caused by a heroic individual is called tragedy. Tragedy is a genre in which the protagonist faces ethical choices with high stakes, often leading to their downfall. It features noble characters, elevated language, and scenes of suffering and death. Examples of tragedy include Shakespeare's Hamlet and the Oedipus Trilogy by Sophocles.