Which of the Following Is an Adaptation of the Avian

Multiple Choice

Which of the following is an adaptation of the avian lung that best helps meet the metabolic demands of flight?

A) Airflow through the avian lung is bidirectional like in mammals.
B) There is more dead space within the avian lung so that oxygen can be stored for future use.
C) Countercurrent circulation is present in the avian lung.
D) Gas exchange occurs during both inhalation and exhalation.