Which of the Following Statements About Unknown Primary Head and Neck

Which of the following statements about unknown primary head and neck tumors is true?

A) PET imaging is able to detect the primary tumor in 60% of cases.
B) Random biopsies will reveal the primary lesion in 40% of cases.
C) Chest imaging will reveal a primary lung tumor in 20% of cases.
D) Tonsillectomy may reveal the occult primary tumor in 20% of cases.