PLS HELP!!!

Why did Twain write "The Celebrated Jumping Frog of Calaveras County" as a frame story?

a.
to show unexpected similarities between educated and uneducated men

b.
to help readers appreciate the story of a famous frog more fully

c.
to show readers how ignorant people in remote Western towns are

d.
to satirize educated, but often prejudiced, men from the East