Answer:
taxi, Empire State Building, corner, Fifth Avenue, at(?) West 54th Street.
Step-by-step explanation:
Well a noun is a person place or thing. Street numbers are nouns as well. A is an indefinite article. I am not a 100% sure this is correct but from my perspective thats what it is. At is either a preposition or a noun. In this situation, I believe it is a noun.