Why Is the Egyptian Site of Fayum Relevant to Oligocene

Why is the Egyptian site of Fayum relevant to Oligocene primates?

A) It is where the vast majority of Old World primate fossils from this period were found.
B) It was the only part of the world where any primates have been found.
C) It is the site where written records of primate existence were found.
D) Archaeologists love to excavate this site due to its beautiful climate.
E) Purgatoriids radiated from here.