Final answer:
The subject of the question is a Shakespearean tragedy.
Step-by-step explanation:
Based on the provided information, the subject of the question is a) Shakespearean tragedy. This is represented by the examples given in the options: The Three Musketeers is a novel written by Alexandre Dumas, while the other options are plays written by different authors. Shakespeare is well-known for his tragedies such as Hamlet and Macbeth.