Which of the following statements about self-awareness is incorrect?

Which of the following statements about self-awareness is incorrect?
 
  a. Self-awareness occurs earlier in children as a function of the amount of social stimulation they receive.
  b. At 15 weeks of age, the home-reared infant in North America is in contact with its mother for about 20 of the time.
  c. At 15 weeks of age, infants in the Ju/hoansi society of South Africas Kalahari Desert are in close contact with their mothers about 70 of the time.
  d. American children develop self-awareness earlier than do Ju/hoansi children.
  e. Self-awareness comes in stages and not all at once.