C. is definitely the right answer
Is this post stated for someone in particular?
The underlined subject of the sentence the skyscraper that was built last year is a noun phrase.When determining the type of phrase, you first need to find its center, of the most prominent word. Here, the center is skyscraper, which is a noun, which means that the whole phrase is a noun phrase.
Answer:
hwywywhwuuwuwh2hnow2bib2i002bi0bbb29ub9bbbbh