An Alexa Skill Builder Is Designing a Skill with an Intent

An Alexa Skill Builder is designing a skill with an intent that needs six slots to be filled. It is unlikely that a user will provide all the slot values in a single utterance, so the slot fulfillment should be split up into a multi-turn conversation. What can the Builder do in the developer console to have Amazon Alexa elicit any missing slots, without specifying each of the slots in the backend code?

A) Keep track of what slots are filled in session attributes, and in the backend code, prompt the user for the missing slots using Dialog.ElicitSlot. Keep track of what slots are filled in session attributes, and in the backend code, prompt the user for the missing slots using Dialog.ElicitSlot.
B) Mark those six slots are required, fill in the necessary prompts, and in the backend code, use the Dialog.Delegate directive until all slots are filled. Mark those six slots are required, fill in the necessary prompts, and in the backend code, use the Dialog.Delegate directive until all slots are filled.
C) Mark those six slots are required, fill in the necessary prompts, and in the backend code, use the Dialog.ConfirmSlot directive until all slots are filled Dialog.ConfirmSlot directive until all slots are filled
D) Mark those six slots are required, fill in the necessary prompts, and in the backend code, use the Dialog.ElicitSlot directive until all slots are filled. Dialog.ElicitSlot