Australopithecus Robustus's Large Masticatory Complex (Large Molars, Face, and Muscles)

Australopithecus robustus's large masticatory complex (large molars, face, and muscles) indicate an adaptation:

A) to eating hard food with sand in it.
B) to eating a great deal of red meat.
C) to eating foods requiring heavy chewing.
D) to gnawing on bones.