$7$

Cleavage Lines help to

A$.$ identify a woman who has previously experienced childbirth.

B$.$ mark the body in case it is bumed so that firefighters can use the unwritten rules to evaluate patients.

C$.$ Guide surgeons in the direction and location of where to cut the patient so as to minimize the damage done.

D$.$ Show the location of the flexure lines during emergency surgery in case a doctor has to perform emergency surgery on people in the plains.