Concept:The word
audacity means boldness or daring, so the opposite is a quality showing fear or lack of courage.
Explanation:The sentence contrasts the family’s known trait with one person’s surprising behaviour.
Since
audacity is a bold or fearless attitude, the missing word must mean the opposite.
Among the options, only
cowardice means lack of courage or timidity.
The other options — irritability, moodiness, and insolence — do not oppose audacity.
Therefore, the completed sentence is: "Obi's family is known for their audacity, so one is surprised at his cowardice."
Answer:A. cowardice