In the Supine Position, Ventilation of the Upper Parts of the Lung

In the supine position, ventilation of the upper parts of the lung

A) has the same distribution as in the upright position.
B) increases from about 1 1/2 to 2 times from upper third to lower third.
C) decreases from about 1 1/2 to 2 times from upper third to lower third.
D) has a gradient from anterior to posterior.