Which Are the Attachments of the Obturator Internus

Which are the attachments of the obturator internus?

A) external surface of the pelvic bone surrounding the obturator foramen to the greater trochanter of the femur
B) external surface of the pelvic bone surrounding the obturator foramen to the lesser trochanter of the femur
C) anterior sacrum to the lesser trochanter of the femur
D) internal surface of the pelvic bone surrounding the obturator foramen to the greater trochanter of the femur