Trephination is the

a. method that supposedly proved that the world is flat
b. procedure where a large hole is created in the forehead so that evil spirits can escape
c. technique that ensure the validity of experimental results
d. theory that mental illness is caused by demonic possession

B - Procedure where a large hole is created in the forehead so that evil spirits can escape.

Explanation:

Trephination is, as the option B describes, an ancient procedure which meant to create a hole in the forhead so that evil spirits can escape. Actually, it helps reduce migrain pain and severe headackes. Nowadays, its a more developed surgical procedure as well.

answer; correlational;

answer; criterion validity