Which of the following statement about The Pilgrim’s Progress is CORRECT?
选项：

A:It’s John Donne’s greatest sermon.
B:This drama is John Bunyan’s great allegory of Christian journey to heaven through the evils of the world
C:It was written as a book of religious instruction for simple folk in the form of allegory and dream.
D:Vanity Fair is a part of this work made by William Thackeray.