Upon reviewing the patient's chart, results of a chest x-ray indicate: "Complete opacification of the left chest with a shift of the trachea and mediastinum to the left." These findings are consistent with which of the following?

A. pneumothorax of the right lung
B. atelectasis of the left lung
C. diffuse pulmonary emphysema
D. right-sided pleural effusion

Ans: B. atelectasis of the left lung