who is the antagonist in this passage?

dear friends,
more than one man, or two, should know those things
circe foresaw for us and shared with me,
so let me tell her forecast; then we die
with our eyes open, if we are going to die,
or know what death we battle if we can. sirens
weaving a haunting song over the sea
we are to shun, she said, and their green shore
all sweet with clover; yet she urged that i
alone should listen to their song. therefore
you are to tie me up, tight as a splint,
erect along the mast, lashed to the mast,
and if i shout and beg to be untied,
take more turns of the rope to muffle me.

a odysseus
b the men
c sirens
d circe