The most precise diagnostic screening procedure for differentiating benign thyroid nodules from malignant ones is:

C. Fine-needle-aspiration biopsy (FNAB).

DISCUSSION: Analysis of multiple series in which patients with thyroid nodules have undergone FNAB has demonstrated a false-negative rate of 2.4% and a false-positive rate of 3.3%. Sensitivity for this method is 92%; specificity 74%. This surpasses the other methods for accurate selection of patients who require surgical resection.