B. Yes/No questions are used when the speaker wants the listener to find out whether the price of information being asked is true or which of the given piece of information is correct. They can also be used to confirm a piece of information. The former two functions are usually asked with a rising tone while the latter with a falling tone. Yes/No questions can be in the form of an interrogation starting with an auxiliary verb or a statement ending with a question tag. Three most commonly used helping verbs to form a question or a tag are verb to be, verb to do and verb to have. As indicated by the name, either yes or no used to start most of the answers to this type of question, especially when short answers are given.