What Purpose Does Singing and Chanting Serve During the Navajo

What purpose does singing and chanting serve during the Navajo American Indian tradition of HEALING?

A) The psychological effects of the singing help the patient feel cared for in a deeply personal way,which aids HEALING.
B) The patient enters a trance,which aids HEALING.
C) The singer accurately predicts the trajectory of the ILLNESS and recovery.
D) The singer brings the family of the affected patient back into harmony with the universe that ultimately heals the patient.