Identifying Ownership: Who Owns This?

Which part of speech is the word "who" in the sentence "who is the owner of this?"

What is the primary purpose of the sentence "who is the owner of this?"

Which word in the sentence "who is the owner of this?" is a noun

The sentence "who is the owner of this?" is written as a question

In the sentence "who is the owner of this?" the word "who" functions as an interrogative pronoun

The sentence "who is the owner of this?" contains five words