Answer:
A. warm yourself by this fire, / rest by this fire, and make you feel safe.
Explanation: In "I Am Offering this Poem" by Jimmy Santiago Baca, the phrase from the poem that best contributes to the comforting tone of the third stanza is warm yourself by this fire, / rest by this fire, and make you feel safe. The author is offering this poem to his loved one. He wants to comfort her with this poem from hunger, from winter's cold, from old age and for the indifference of people.