What Is the Advantage of Having Grape-Like Clusters Called Alveoli

What is the advantage of having grape-like clusters called alveoli as part of the respiratory system?

A) Alveoli allow for an increase in surface area, which maximizes gas exchange.
B) Alveoli are circular in structure, which is ideal for maximal gas exchange.
C) Because alveoli are shaped like grapes, this allows for thinner walls, thereby facilitating gas exchange in the lungs.
D) The shape of alveoli allows capillaries to be in closer proximity to gases, which facilitates gas exchange.