The correct answer is B. annoyed.
Nettled means annoyed or irritated. The teacher was annoyed by the rowdiness of the boys because it was disruptive to the class and disrespectful to her.
Pleased means feeling satisfaction or happiness. The teacher would not be pleased by the rowdiness of the boys because it is not a positive behavior.
Disgusted means feeling extreme revulsion or disapproval. The teacher would not be disgusted by the rowdiness of the boys because it is not a behavior that is typically considered disgusting.
Perplexed means confused or puzzled. The teacher would not be perplexed by the rowdiness of the boys because it is a common behavior for young boys.