Which quotation is a key part of hamlet’s “to be, or not to be” soliloquy?
a. “there's something in his soul, / o'er which his melancholy sits on brood”
b. “whether 'tis nobler in the mind to suffer / the slings and arrows of outrageous fortune”
c. “am i then revenged, to take him in the purging of his soul, / when he is fit and season'd for his passage? ”
d. “give me that man / that is not passion's slave, and i will wear him / in my heart's core? ”

The quotation which is part of Hamlet’s “To be, or not to be” soliloquy is option B.

To be, or not to be, that is the question:

Whether 'tis nobler in the mind to suffer

The slings and arrows of outrageous fortune,

Or to take arms against a sea of troubles

And by opposing end them.

Hamlet's greatest ans most known soliloquy is the source of more than a dozen everyday expressions.

Basing on Hamlet's speech, we can notice that his notions of "being" and "not being" are rather complex. He doesn't simply ask if life or death is preferable; it's hard to clearly distinguish the two "being" comes to look a lot like "not being," and vice versa.

this answer was editing it cause i couldn't delete!