In E-Discovery,how Are Interrogatories Used to Help Prepare for Depositions

In e-discovery,how are interrogatories used to help prepare for depositions?

A) Interrogatories tell the opposing party where and when the depositions will occur.
B) All of the necessary questions can be asked in interrogatories, making a deposition unnecessary.
C) Interrogatories may be asked in-person, before written questions are submitted in the deposition.
D) A party can be asked to identify persons who are responsible for electronic documents.