In about one-third of cases, a sensory warning sign precedes a migraine. This warning sign is called a(n)
A) prelude.
B) halo.
C) indicator.
D) aura.
Question 2
Research suggests that migraines may be triggered as a result of
A) vascular abnormalities in the brain as a result of viral infection or physical trauma.
B) neurological abnormalities due to genetic mutation of a single gene.
C) possibly genetic biochemical and inflammatory processes within the brain.
D) a combination of physiological and psychological factors.