Question

read the following excerpt from bannekers letter (refer to your literature textbook page 51)
\i suppose that your knowledge of the situation of my brethren is too extensive to need a recital here; neither shall i presume to prescribe methods by which they may be relieved, otherwise than by recommending to you and all others, to wean yourselves from those narrow prejudices which you have imbibed with respect to them, and as job proposed to his friends, put your soul in their souls stead; thus shall your hearts be enlarged with kindness and benevolence towards them; and thus shall you need neither the direction of myself or others, in what manner to proceed herein.\ (banneker 51)
what is the purpose of the phrase \thus shall your hearts be enlarged with kindness and benevolence towards them\ in the paragraph above?
banneker is saying that if his readers physical hearts were large enough, they would care about the situation of the slaves.
banneker is encouraging slaves to fight for their freedom
banneker is using a metaphor to persuade jefferson that if jefferson was filled with more of the emotions of kindness and compassion towards the slaves, then he would oppose slavery
banneker is using figurative language to say that slaves are unhappy

Explanation:

The phrase "Thus shall your hearts be enlarged with kindness and benevolence towards them" is a metaphor. Banneker is not referring to physical hearts but rather to the emotional and moral capacity (the "heart" as a symbol of emotions and moral sense) of the readers. He is persuading Jefferson (and others) that if they fill themselves with kindness and compassion (enlarge their metaphorical hearts) towards slaves, they would oppose slavery. The first option about physical hearts is incorrect as it takes the phrase literally. The second option about slaves fighting is not related to this phrase. The fourth option about slaves being unhappy is not the focus of this particular phrase's purpose.

Answer:

Banneker is using a metaphor to persuade Jefferson that if Jefferson was filled with more of the emotions of kindness and compassion towards the slaves, then he would oppose slavery.