Select the most appropriate option to fill in the blank.

The old telephone ______ nobody wants has been thrown into the junkyard.

which

The most appropriate option to fill in the blank is which.

The sentence is about an old telephone that nobody wants. The word "which" is a relative pronoun that is used to refer to a specific thing. In this context, the speaker is saying that the old telephone, which nobody wants, has been thrown into the junkyard.

The other options are not as appropriate.

• What is a pronoun that is used to refer to an unknown or unspecified thing. This is not the most appropriate option because the speaker is referring to a specific thing, the old telephone.
• Whom is a relative pronoun that is used to refer to a person. This is not the most appropriate option because the speaker is not referring to a person, they are referring to an object, the old telephone.
• Who is a pronoun that is used to refer to a person. This is not the most appropriate option because the speaker is not referring to a person, they are referring to an object, the old telephone.