When evaluating a 12-year-old child with a 10-day history of rhinitis and facial pain, the testing most effective in determining sinusitis is:
A) Other upper respiratory tract conditions can result in abnormal radiographic findings, so sinus aspirate is the only positive test
B) Radiographic studies are most accurate in the early stages of a respiratory infection
C) X-ray opacities in the sinuses confirm bacterial sinusitis
D) Some mucosal thickening can be seen only on computed tomography or magnetic resonance imaging, so these studies should be ordered in place of plain films