What is the most likely reason "The Monk's Tale" is full of parables? (APEX)

A.Parables, unlike prior forms of storytelling, tended to focus on broad themes rather than on morals. 
B.Parables were starting to replace fables as the popular form of moral storytelling in the 14th century. 
C.Parables cast animals as characters, which 14th century audiences found safe compared to fables. 
D.Parables were commonplace in Chaucer's time, and audiences would have found them familiar.