Choose the option that best completes the sentence.
My uncle is not sure ____ the strange guests were.
Answer Details
The most suitable option to complete the sentence "My uncle is not sure ____ the strange guests were." is "who". Here's the explanation:
The word "who" is used when referring to people and asking about their identity. In the given sentence, "the strange guests" are people whose identity is uncertain to the uncle. Therefore, the correct word to fill the blank is "who".
In contrast:
"Which" is usually used when there is a specific range of options or a limited set of items to choose from.
"Whom" is a formal term often used in place of "who" when it's the object of a verb or preposition.
"What" is used to ask about things or information, rather than people.