You know what is singular and plural I think so
So in singular we are using for one person,thing,place or animal
In plural we are using two or more than two person,thing,place or animal

So, city is a place
City is in singular but our question Is for cities
Cities is in plural because cities means many city or a number of cities

Introduction:
In the English language, nouns are words that refer to people, places, things, or ideas. They can be classified into different categories based on their characteristics. One such classification is based on number, which includes singular and plural nouns. Additionally, nouns can also be possessive, indicating ownership or association with someone or something. In this explanation, we will determine the correct classification for the noun "cities" based on the given options.

Singular noun:
A singular noun refers to a single person, place, thing, or idea. Examples of singular nouns include "dog," "book," and "sun." Since "cities" refers to more than one city, it cannot be classified as a singular noun.

Plural noun:
A plural noun refers to more than one person, place, thing, or idea. Examples of plural nouns include "dogs," "books," and "suns." Since "cities" refers to multiple cities, it can be classified as a plural noun.

Singular possessive noun:
A singular possessive noun is a noun that shows ownership or association with a single person, place, thing, or idea. It is formed by adding an apostrophe and the letter "s" ('s) to the end of a singular noun. For example, "dog's" indicates that something belongs to a single dog. Since "cities" does not show ownership or association with a single city, it cannot be classified as a singular possessive noun.

Plural possessive noun:
A plural possessive noun is a noun that shows ownership or association with more than one person, place, thing, or idea. It is formed by adding an apostrophe (') after the "s" at the end of a plural noun. For example, "dogs'" indicates that something belongs to multiple dogs. Since "cities" refers to more than one city and can indicate ownership or association with multiple cities, it can be classified as a plural possessive noun.

Conclusion:
Based on the given options, the correct classification for the noun "cities" is a plural possessive noun. This is because it refers to multiple cities and can show ownership or association with those cities.