The skyscraper that was built last year has the most extraordinary architecture. the underlined subject of this sentence is an
adverbial phrase.
a noun phrase.
a prepositional phrase.
a verb phrase.

The answer to your question would be that the underlined subject of the sentence is a noun phrase.

Explanation:

The complete subject of the sentence above is the following one: The skyscraper that was built last year. This subject is postmodified by a restrictive relative clause "that was built last year", but the subject is still a noun phrase.

i don't know exactly what it's asking, but either one of these pairs would

her; him

edith; sam

hope this ya

what are your options ?

i would say years or cherry blossoms