Which of the Following Statements Is True About a Prior

Which of the following statements is true about a prior inconsistent statement being used for impeachment purposes?

A) The cross-examiner must have a reasonable basis for believing that the earlier statement was made by the witness.
B) Under the federal rules, the statement must be disclosed to the adverse party's attorney on request before the asking about the inconsistent statement on cross-examination.
C) Both a and b are true.
D) Neither a nor b is true.