During the Renaissance, Italian cities became centers of

A. photography

B. warfare

C. banking

D. transportation

A) - photography was not developed yet!

b) rather not, renaissance was a time of art and development, not wars.

c) I think that this is the best answer! Renaissance was a time when the Italian cities were very rich - and banking was a way of dealing with this richness. In fact, it is sometimes thought that modern banking started just like Renaissance did - in Florence. (and in Venice and in Genoa)