The so-called "grandmother hypothesis", based on studies of African hunter-gatherer groups, suggests that infertile women are vital for successful child-rearing despite being unable to produce children themselves.

Choose your answer: based on the paragraph above can we conclude that "The so-called "grandmother hypothesis" originated in the 1950s."?

OPTIONS:
(I). Yes;
(II). It's impossible to say;
(III). No;
I think the answer is
(II).