Read the text and determine if the sentence is true (see options at the end):

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.

Sentence: Grandmothers like to bake cookies.
Pick your answer from: --Yes; --It's impossible to say; --No;
It's impossible to say