Answer to Question 1
ANS: C
In the posteroanterior projection, the diameter of the heart shadow should not exceed one-half the diameter of the chest.
Answer to Question 2
ANS: A
An overpenetrated x-ray overexposes the film, leaving the lung parenchyma black and no ability to visualize the peripheral blood vessels. This overpenetration will make evaluation of the lung parenchyma far more difficult.