Final answer:
Infants are at the highest risk of dying from SIDS between 2-4 months of age. To reduce the risk, it is recommended that infants sleep on their backs in a crib free of loose bedding and that parents avoid exposure to smoke.
Step-by-step explanation:
The infant age at which the risk of dying from sudden infant death syndrome (SIDS) is highest is B) 2-4 months. Infants younger than 12 months are at the highest risk for SIDS, and specific factors such as premature birth, smoking within the home, and hyperthermia contribute to the likelihood of SIDS. To reduce the risk, parents are advised to ensure infants sleep on their backs, avoid overheating, and maintain a smoke-free environment.