The study of Dr. Ruth Mace and Dr. Rebecca Sear shows that a child's growth may be affected ______.

A．The sufferings of eider females have been ignored for a long time.
B．Old women's special role in society has been underestimated.
C．Paternal grandmothers are equally important for a child as maternal ones.
D．There are low proportions of older adults among "primitive" cultures.

A．was interested in studying the lives of the old women in Australia
B．admired the hard working elder females he saw in Australia
C．was the first to recognize the crucial role played by grandmothers
D．loathed the old women he saw in Australia for their ugliness