Concept:The phrase "a green horn" is an idiom for someone who is new, untrained, or lacking experience.
Explanation:Fatou's awkward behavior shows that she is a green horn.
Awkward behavior often suggests that a person is not familiar with a particular situation.
A green horn originally meant a young animal with newly formed horns.
In everyday English, it refers to a beginner, a newcomer, or an inexperienced person.
Such a person may seem naive, immature, or easily confused because they have not learned how things are done.
Among the options, "arrogant" means proud, "inattentive" means careless, and "cautious" means careful.
None of these match the sense of being newly exposed to something.
Therefore, the most appropriate meaning of "green horn" here is a lack of experience.
Answer:Fatou is inexperienced.
Option B is the correct answer.