Answer:
D. End by telling the interviewer that David is hoping to hear from the company soon.
Explanation:
After the interview is over and there is nothing left which interviewer or David has to ask, He should ask for leave in a very appropriate manner.
Of the given options, option D is the best way for next step i.e. asking appropriately for the permission to leave.
Options A and C will certainly annoy the interviewer. The interviewer is not ethically or professionally bound to answer such questions. They are in the process of hiring someone, but at this stage they will not comment anything. Even if they are 99% sure to hire David, they will say no such thing. Similarly, information about the number of candidates competing for the same job may be confidential, and asking this would annoy the interviewer.
Option B is incorrect because, hiring is not usually done right after the interview. The company usually takes some time, and the hiring committee usually discusses certain aspects and factors before making final decision.
Option E is incorrect, because leaving without saying a word will leave very bad impression on the interviewer. David needs to get his permission by appropriately asking for this.