The correct option is C Possibly real but scientifically unproven
The first passage puts emphasis on family centered programs and policies because "science has added stunning revelations about human development from birth to age three, confirming that parent and other adult caregivers play a critical role in influencing the child's development". Whereas the second passage states that Nelson and Bloom say that, "It may be useful to question the simplistic view that the brain becomes unbendable and increasingly difficult to modify beyond the first few years of life. Although clearly much of brain development occurs through the first years of life, the brain is far from set in its trajectory, even at the completion of adolescence." which contents the idea that "parents have only a single, biologically delimited, once-in-a-lifetime opportunity to help their children build better brains." In this context, option C is the best answer for the given question.