In this excerpt from edgar allan poe's "the raven," what does the biblical reference to the healing “balm in gilead” signify?

"prophet! " said i, "thing of evil! —prophet still, if bird or devil! —
whether tempter sent, or whether tempest tossed thee here ashore,
desolate, yet all undaunted, on this desert land enchanted—
on this home by horror haunted—tell me truly, i implore—
is there—is there balm in gilead? —tell me—tell me, i implore! "
quoth the raven, "nevermore."

a. the speaker’s desire to cure the raven of its inability to say anything other than “nevermore”
b. the speaker’s desire to cure himself from the pain caused by lenore’s death
c. the speaker’s desire to bring lenore back to life
d. the speaker’s desire to cure himself from his mental illness and hallucinations