The correct option is A President
A notice ends with the designation of the person signing off. Hence, blank 5 must be filled with the designation of the person, Naresh Sharma.
Option B: 'President' is a designation, it indicates the position of the person who has written the notice, in relation to the society. Hence B is the correct option.
Option A: 'New Delhi' is a city, the notice does not end with the location, but the title or authority with which the person writes. Hence A is incorrect.
Option C: This term 'undersigned' is used as a declaration in important documents. (For example: I, the undersigned, agree to the terms and conditions.) It is not used at the end of a notice. Hence C is incorrect.
Option D is incorrect because the answer lies in B.