How do metaphors and extended metaphors differ?

AWhile a metaphor is limited in length, an extended metaphor is developed over the course of a poem.

BWhile a metaphor describes the way someone thinks or feels, an extended metaphor compares multiple unlike things.

CWhile a metaphor conveys a set of ideas, an extended metaphor conveys a single idea across the poem.

DWhile a metaphor makes a comparison, an extended metaphor shows the attitude of a text toward its subject