The answer is C: adjective.
The instances of situational irony that occur in the above passage are:
The aunt expects the boy to accept her explanations, but he does not.
The aunt expects the boy to be interested in the cows, but he is not.
A situational irony is a form of irony in which the actions have an opposite effect of what it is intended. The outcome of the situation is totally different to what it is expected. In the above excerpt, the answers which the boy gets from his Aunt and the way he deals with those answers are an example of situational irony.
It is usually the exposition.
Answer:
The square root of 9 is 3.
