Which of the Following Structural Differences Between Children and Adults

Which of the following structural differences between children and adults predisposes children to middle ear infections?

A) The fluid-filled cochlea is less developed in children than in adults.
B) Children have shorter, more horizontal, and more flaccid eustachian tubes.
C) The outer ear of children is shorter and has fewer barriers, such as hair, in the ear.
D) The semicircular canals are straighter and shorter in a child's ear.