What is an effect of chaucer's decision to use a pilgrimage as the central premise for the canterbury tales?

A.it sets up an expectation that exempla, which were common in didactic medieval literature, will be part of the story. 
b.it allows chaucer to write his poem in english because he is capturing the speech of english commoners. 
c.it provides chaucer with an opportunity to write about characters that represent a wide range of social classes. 
d.it makes the messages of the pilgrims more persuasive because a reader in chaucer’s time would have respected them for their fervent religious beliefs.