Acquired, symmetric hyper pigmentation of the sun exposed skin of the face & neck which is strongly associated with pregnancy & use of oral contraceptives is called as_______________?

A. Greatest in the middle-third of a single rotted tooth
B. Greatest in the middle-third of a multirooted tooth
C. A net like plexus that runs closer to the cementum than to the bone
D. A net like plexus that runs closer to the bone than to the cementum