Answer:
He should restate a positive point that he would like the interviewer to know.
Explanation:
In an interview it is very important to create an impression that one can recover from a negative situation and stay positive.
In the given scenario where Dario was unable to answer the interviewer's final question because it was slightly technical and he did not know the answer, the way to express positivity is to restate a positive point that he will like the interveiwer to know.
In the interviewer's mind the conversation will now end on a positive note.