Sparta joined with Athens because Sparta was . a.
too weak to confront the Persians alone.
c.
afraid that Persia threatened Spartan miltary control of Greece.
b.
planning defeat the Persians first and then attack Athens.

a) too weak to confront the persians alone

Explanation:

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.

the church governed the society after the empire fell.   constantine took charge of rome and ended the confusion which had over religion and made christianity as the only religion and that started ruling the roman empire. he also divided the empire into two and fortified the eastern part.   he ruled the eastern part.