I read a definition of "sarcastic interrogatives" at this link which was:
stock questions with glaringly obvious yes or no answers.
Now, most of the dictionaries define stock, as an adjective, as
(of an excuse or answer) often used because of being convenient and therefore being unoriginal.
And also, the word "stock", in most of the examples that I read, was modifying an answer, not a question. A "stock question" would imply that it is often asked whenever it is convenient which is not basically what the author wanted to say, although what author wanted to say was clear from the context. Am I right?