Amicus Curiae Briefs Have Some Advantages Over Expert Testimony

Amicus curiae briefs have some advantages over expert testimony. Which of the following is NOT such an advantage?

A) Research studies cited in the brief are listed in a reference section and can be checked out.
B) An amicus curiae brief is typically written by a team of researchers.
C) Amicus curiae briefs are often reviewed by the relevant professional organization.
D) Amicus curiae briefs are typically more expensive to produce than the expert testimony.