How should infant passengers be secured in an aircraft?

Infant passengers should be secured in an aircraft using a method that ensures their safety during the flight, which typically means they should be secured in an approved child safety seat. The correct answer emphasizes the responsibility of an adult to hold the infant, but it's essential to understand that infants should ideally be secured in a proper child safety seat that is designed for use in an aircraft and can be attached using the aircraft's seatbelt.

When considering the importance of securing an infant correctly, it's crucial to recognize that their size and inability to hold on during turbulence or other in-flight movements make it unsafe for them to be unattended or to be held only in the arms of an adult. The use of specific child safety seats ensures that they are restrained properly and can help prevent injury in the event of turbulence or an unexpected event during the flight.

While the method in the selected answer does mention holding an infant in an adult's arms, it is not the safest or most recommended approach for their security and well-being in an aircraft setting.