A resident physician is performing a pelvic examination on a young female. The fingers of one of the physician's hands are in the patient's vagina, palpating the cervix. The other hand is pressing on the abdomen. With the palm of this hand, the physician feels a bony structure in the lower midline. This structure is most likely which of these?

1. A)Sacrum
2. B)PubisGABARITO
3. C)Coccyx
4. D)Ischium
5. E)Ilium