At Which Level Should the Central Ray Enter the Base $3 / 4$

At which level should the central ray enter the base of the skull for the SMV projection of the sinuses?

A) $3 / 4$ inch posterior to the level of the EAM
B) $3 / 4$ inch anterior to the level of the EAM
C) $3 / 4$ inch below the mental protuberance
D) 1 inch below the mental protuberance