Answer:
Answer is C. Tattoo their faces.
Step-by-step explanation:
This act of tattooing faces in the hope of repelling invaders and discouraging kidnapping has been described by the psychologists as an abnormal behavior.
An abnormal behavior is an usual behavior which does not go along as social expectations. And one of the factors that has been considered as the cause is mental disorder which has genetically inherited.
Note that, this act of tattooing faces has been abolished since 1960s by the Burma socialists.