Florence is the city-state that benefited greatly from trade during the 14th century. Option A is correct.
Consequently, it became one of the wealthiest cities of its time.
A city-state is a region that is independently ruled by a major city. During the Renaissance Italy was governed by numerous powerful city-states. These constituted some of the largest and richest cities in all of Europe. Some of the more important city-states included Florence, Milan, Venice, Naples, and Rome.