Answer:
B. It reveals how Bob allows the policeman to see him and recognize him as a wanted criminal.
Step-by-step explanation:
This is the statement that best explains O. Henry's choice to have Bob light a cigar while talking to the policeman. In this story, O. Henry wanted to show that the policeman was able to recognize the man as a wanted criminal. The way in which he does this is by letting him light a cigar and in this way illuminate his face.