The correct answer is A) Infants to six-year-olds.
After an emergency, children of this age group often revert back to infantile behavior: "Infants to six-year-olds."
Psychologists have a name for this. They called regression behavior. This kind of behavior is common after the kid has lived a stressful situation, a traumatic experience or an emergency. After the experience, they find it difficult to control their find their emotions. They can express aggression, tantrums, nervous breakdown or even violent conduct.