What Is the Primary Reason That Preschool Children Are More

What is the primary reason that preschool children are more prone to ear infections than adults?

A) They often have enlarged tonsils that block the Eustachian tube
B) They tend to have poor oral hygiene, making them more prone to infection
C) They have a less efficient immune system than adults
D) The inclination of the Eustachian tube is less sloped than an adult's
E) They have a smaller middle ear space than an adult