If a Dark Radiolucent Shadow Obscures the Apices of the Maxillary

Multiple Choice

If a dark radiolucent shadow obscures the apices of the maxillary teeth,the:

A) patient's lips were not closed on the bite-block during the exposure.
B) patient's tongue was not in contact with the palate during the exposure.
C) patient's head was posterior to the focal trough.
D) patient needed to swallow.