In the given sentence, the first thing we need to take note of is capitalizing the first letter of the sentence i.e. P (Please). We use a question mark for an interrogative sentence and a full stop for an imperative sentence that emphasizes a request. The given sentence conveys a request, therefore, we should use a full stop at the end of the sentence. Also, the first letter of ‘sir’ need not be in uppercase since it is not a proper noun. Therefore options A and C are incorrect. Further, a comma is used to indicate the separation of ideas or elements and to differentiate the different parts of a sentence, thereby avoid confusion while reading. In the given sentence, a comma needs to be placed after ‘Please’ since it is the introductory phrase; hence it needs to be set off from the main clause. Similarly, we should place a comma before ‘sir’ to indicate who the request is addressed to, thereby avoid misreading or confusion. Therefore option B is correct, while option D is incorrect.