Billy Witnessed a Hit-And-Run but Is Gravely Ill with Cancer

Billy witnessed a hit-and-run but is gravely ill with cancer. Xavier, who was injured in the accident, would like to preserve Billy's testimony for trial in case Billy dies before the trial date. What should Xavier do?

A) Send interrogatories to Billy.
B) Take Billy's deposition.
C) Send a request to admit to Billy that the accident was the defendant's fault.
D) Have a conference with the judge and Billy.
E) There is nothing Xavier can do.