I would go with the second option
The fate of cities varied greatly, with periods of significant decline and periods of increased urbanization.
Explanation:
The fate of cities varied greatly, with periods of significant decline, and with periods of increased urbanization buoyed by rising productivity and expanding trade networks.
Multiple factors contributed to the declines of urban areas in this period.
Examples of these factors:
• Invasions
• Disease
• The decline of agricultural productivity
• The Little Ice Age
Multiple factors contributed to urban revival.
Examples of these factors:
• The end of invasions
• The availability of safe and reliable transport
• The rise of commerce and the warmer temperatures between 800 and 1300
• Increased agricultural productivity and subsequent rising population
• Greater availability of labor also contributed to urban growth
While cities in general continued to play the roles they had played in the past as governmental, religious, and commercial centers, many older cities declined at the same time that numerous new cities emerged to take on these established roles.
Source 1
"Christendom had recovered from . . . when the Tartar cataclysm had threatened to engulf it. The Tartars themselves were already becoming an object of curiosity rather than of fear. . . . The frail Latin throne in Constantinople was still standing, but tottering to its fall. The successors of the Crusaders still held the Coast of Syria. . . . The jealousies of the commercial republics of Italy were daily waxing greater. The position of Genoese trade on the coasts of the Aegean was greatly depressed . . . Venice had acquired [power there by expelling] the Greek Emperors. . . . But Genoa was biding her time for an early revenge, and year by year her naval strength and skill were increasing. Both these republics held possessions and establishments in the ports of Syria. . . . Alexandria was still largely frequented in the intervals of war as the great emporium of Indian wares, but the facilities afforded by the Mongol conquerors who now held the whole tract from the Persian Gulf to the shores of the Caspian and of the Black Sea, or nearly so, were beginning to give a great advantage to the caravan routes.”
Henri Cordier’s annotated translation of The Travels of Marco Polo, 1920