Final answer:
Hamlet's fifth soliloquy is marked by a shift towards revenge, as he contemplates killing Claudius but ultimately decides against it, considering the act unjust at that moment. This reflects a difference from his earlier introspective soliloquies, though existential themes persist.
Step-by-step explanation:
In Hamlet's fifth soliloquy, the circumstances of this soliloquy differ from those surrounding the previous four primarily in that it displays a shift towards revenge. Earlier soliloquies are more reflective, focusing on existential contemplation and Hamlet's indecision. The fifth soliloquy, often called the "Now might I do it pat" soliloquy, finds Hamlet with an opportunity to kill Claudius as he prays. Nonetheless, Hamlet decides not to act, reasoning that killing Claudius while he is praying would send him to heaven, which Hamlet sees as unjust revenge. This soliloquy is not noted for occurring in a public setting nor in the presence of Ophelia, so the options a and b are incorrect. The theme of existential contemplation has recurred throughout Hamlet's soliloquies and persists here as well, so option d is not a distinguishing factor.