Asking Questions, Particularly Open-Ended Ones, Is One of the Simplest

Asking questions, particularly open-ended ones, is one of the simplest ways to make better conversation because

A) asking a good series of questions shifts attention to the other person.
B) asking questions shows you are interested in the other person.
C) replies to open-ended questions give extra information that can be used to ask other questions or lead to other topics of conversation.
D) of all of these reasons.