Answer:
B. If you come here when the moon is full, the legend goes you can see the ghost of an old sailor walking along the shore.
Explanation:
B is the correct answer, because the comma is basically directly there to add a pause to the sentence, between the cause and the effect.
Chaucer depicts the pilgrims of the day as the day as always traveling in groups.
A, he really emphasizes his point by repeating that same phrase several times in his speech and uses that to get it across to the people listening