The Lobes of a Lung Are Easy to Recognize and Distinguish

The lobes of a lung are easy to recognize and distinguish from one another because

A) they are separated by fissures.
B) carbon from the air accumulates between and outlines the lobes in most people (even if they breathe almost-unpolluted air) .
C) they all have slightly different colors.
D) each is supplied by a primary bronchus, and the primary bronchi are easy to find.