What is the overall tone of this excerpt from "when we two parted" by lord byron?
they name thee before me,
a knell to mine ear;
a shudder comes o'er me—
why wert thou so dear?
they know not i knew thee,
who knew thee too well: --
long, long shall i rue thee,
too deeply to tell.
in secret we met—
in silence i grieve,
that thy heart could forget,
thy spirit deceive.
if i should meet thee
after long years,
how should i greet
with silence and tears.
a: somber
b: distressful
c: bittersweet
d: joyful