[help] another old GMAT CR Q

vantreal

Children born blind of deaf and blind begin social similing on roughly the same schedule as most children, by about three months of age.

The information above provides evidence to support which of the following hypotheses?

(A) For babies, the survival advantage of smiling consists in bonding the caregiver to the infant.

(B) Babies do not smile when no one else is present. (irrelevant)

(C) The smiling response depends on an inborn trait determining a certain pattern of development.
            

(D) Smiling between persons basically signals a mutual lack of aggressive intent. (irrelevant)

(E) When a baby begins smiling, its caregivers begin responding to it as they would to a person in conversation.

why (C)?

gonghao

A and D both involves in some new element, caregiver, who has never happeared in the argument.

C:connect the infants and smiling would be the answer to this question.

vantreal

sorry, but I think I might have misunderstood the answer choice (C).
    

(C) The smiling response depends on an inborn trait determining a certain pattern of development.

does it mean the smiling response depends on an inborn trait which determines a certain pattern of development?

if it does, then i think it might weaken the hypotheses,

because normal children and children born deaf or deaf and blind begin social similing at almost the same time, smiling response happens no matter a child is normal or born deaf....