What is a descriptive adjective a) any word with more than one syllable b)any word that included a noun and an adjective c)two words joined together by a hyphen d) two words separated by a colon

Option 'b' is correct.

Step-by-step explanation:

Descriptive adjectives are those adjectives that can be defined as the type of person, shape of a person, color of any thing , that is generally to describe a person, place, animal or thing.

So, It is any word that included a noun and an adjective.

For example:

The old man asked the pretty girl for food.

here, old is a descriptive adjective to describe a man.

And pretty is a descriptive adjective to describe a girl.

Hence, Option 'b' is correct.