Noun phrases are two or more words that work as nouns, this means that all of the words that form the phrase are related to create a noun, a cool, refreshing glass of homemade lemonade, eventhough it´s just a single object it has several words describing it and it makes a noun phrase. Other examples of Noun phrases are:
The answer would be B. a cool, refreshing glass of homemade limeade. Because a noun is a person place or thing, B is the only one describing a person place or thing. The thing is limeade.