Which of the Following Most Accurately Describes the Issuing of Witness

Which of the following most accurately describes the issuing of witness summons?

A) You must issue witness summons to all witnesses and experts who are giving oral evidence at trial including your client.
B) Witness summons can only be served by the court.
C) For a witness summons to be valid it must be served at least 14 days before trial.
D) If a witness fails to attend trial having been served with a valid witness summons, he may either be fined or found to be in contempt.