Which Situation Might Increase the Risk of a Child Succumbing

Which situation might increase the risk of a child succumbing to sudden infant death syndrome?

A) A six-month-old begins to roll from his back to his belly.
B) An infant is put to bed on her back instead of on her belly.
C) Family pets sleep in the same room as a new baby.
D) Caregivers of an infant in full-time daycare are cigarette smokers.