Question

read the excerpt from dr. martin luther king’s “letter from birmingham jail.”
just as the apostle paul left his village of tarsus and carried the gospel of jesus christ to the far corners of the greco roman world, so am i compelled to carry the gospel of freedom beyond my own home town.
why does king use this allusion?
to emphasize the morality of his cause
to define the purpose of his travel
to compare the goals of famous leaders

Explanation:

King draws an allusion to the Apostle Paul, whose mission was rooted in a morally charged, widely respected religious cause. By linking his own work for freedom to Paul's spread of the Christian gospel, King frames his civil rights efforts as a similarly moral, purpose-driven mission that transcends local boundaries. The other options are incorrect: the allusion is not focused on travel purpose, nor is it about comparing goals of famous leaders generally.

Answer:

to emphasize the morality of his cause