Final answer:
Historical accounts imply that Milan's population declined significantly due to the 'Second Pestilence' plague of 1359-63, which aligns with the severe demographic changes reflected in the given time frame of 1330 to 1500.
Step-by-step explanation:
The question asks which city's population declined the most between 1330 and 1500, offering choices including Paris, Palermo, Naples, and Florence. Based on historical accounts, particularly concerning the impact of the plague during the 14th and 15th centuries, a significant population decline was noted in several Italian cities. Milan experienced a catastrophic demographic decline due to the plague, especially during the 'Second Pestilence' of 1359-63. This is confirmed by the account of Francesco Petrarca, who documented the severe impact of the epidemic on Milan, describing it as almost completely emptied.
Additionally, references to the plague's effects in Cairo and the resilience of Florence against external threats indicate that Milan suffered significant population declines related to the plague. Given that Naples is listed with a population of over 430,000 by the end of the 18th century and no specific decline is documented for the other mentioned cities during the relevant period, Milan, which is not directly listed but can be inferred from the context, likely experienced the most severe demographic reduction.