What is the purpose of the extended metaphor in ‘Hope’ is the thing with feathers?

Question

What is the purpose of the extended metaphor in  ‘Hope’ is the thing with feathers ?

Answer

It allows the poet to show off their literary skills.

Answer

It allows the poet to gradually build up the comparison by drawing multiple connections between an abstract idea and concrete thing.

Answer

It helps to set the mood of the poem.

Answer

It builds tension in the poem.

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