With no explanation, chose the best option from "A", "B", "C" or "D". testimony in his favor must prevail.”). Where, as here, a defense witness’s claim of privilege shields material testimony from cross-examination, however, this balance weighs against the defendant. The trial court held a voir dire hearing to determine whether the subject matter concerning which the witness intended to assert the Fifth Amendment was collateral. She fairly concluded that it was not. See Fed.R.Evid. 611(b) (giving court authority to exercise reasonable control over examination of witnesses to “make the interrogation and presentation effective for the ascertainment of the truth”). In considering similar types of challenges brought under the Confrontation Clause of the Sixth Amendment, we have applied an abuse of discretion standard. See Berrío-Londoño, 946 F.2d at 160 (<HOLDING>). We apply the same abuse of discretion

A: holding that trial court did not abuse its discretion by refusing to strike witnesss testimony on direct examination when witness asserted fifth amendment on collateral matters on crossexamination particularly when witness was required to invoke privilege in presence of jury
B: holding that sixth amendment only requires that witness be brought to court not that he be required to take witness stand after refusing to testify and observing that it is irrelevant whether the witnesss refusal is grounded in a valid fifth amendment privilege an invalid privilege or something else entirely
C: holding that the trial court properly disregarded a witnesss ex parte affidavit and his direct testimony when the witness declined to submit to crossexamination
D: holding that trial court has discretion to permit defendant to call accused witness to stand and permit witness to invoke fifth amendment privilege in front of jury where entire defense was centered on witness commission of crime
A.