Relating to the Economics in Practice on Page 338: Crying

Relating to the Economics in Practice on page 338: Crying babies on an airplane impose a negative externality on those sitting around them. Which of the following policies would help to internalize the externality?

A) Provide discount tickets for babies and young children.
B) Evenly disperse the babies and young children throughout the plane so as to minimize the impact of their crying on any one passenger.
C) Impose a minimum flying age of 5 years old.
D) Charge a higher ticket fee for babies and young children (under 5 years of age) than for all other passengers.