; and (II) for the preparation of a final ILO classification report for the chest radiograph. (iii) Additional reviewers If individual ILO classifications reported by each B Reader of a B Reader Panel diverge from each other by more than an acceptable variance, as determined by protocols established under subsection (h), the Director shall assign additional B Readers to the applicable B Reader Panel or convene an additional B Reader Panel, as the Director determines necessary, to assure that the ILO classification report of the initial B Reader Panel is accurate and scientifically valid. (iv) Use of known positive and negative x-rays as a quality control tool The quality assurance program under this paragraph shall use pre-read radiographs, for which ILO classifications have been previously established as external standards, with sufficient frequency in order to assure that B Readers on B Reader Panels read radiographs that are borderline positive or negative for complicated pneumoconiosis or progressive massive fibrosis (large opacities greater than or equal to category A of the ILO classification) with accuracy and consistency. (v) Blind readings In reading a radiograph to make an ILO classification, a B Reader shall be blinded from the origin of the radiograph. (B) Continuous improvement The Director shall establish a process for providing feedback to B Readers in the B Reader Pool with respect to their performance in providing ILO classifications and provide suggestions for improvement. (c) Creation and maintenance of B Reader Panel Pool (1) Establishment The Director shall establish a B Reader Panel Pool to be used for the B Reader Panel Program under this section. The Director shall solicit and select physicians who are B Readers for inclusion in the B Reader Panel Pool. (2) Selection and retention for B Readers on B Reader Panel Pool (A) In general The Director shall establish and disclose criteria by which B Readers are selected and retained within the B Reader Panel Pool, including minimum standards of