Correct answer = C.
<p>  While a hemorrhagic effusion is
     characteristic of PE, it is seen only rarely.  Most commonly,
     pleural fluid is exudative in PE although up to 15% of cases
     will be transudative.  The most common radiographic
     abnormality in PE is the combination of plate-like
     atelectasis, elevation of the hemidiaphragm, and a small
     pleural effusion.  Uncomplicated effusions may be observed
     without chest tube drainage in all cases, including those
     associated with PE.