Fill in the blank with most appropriate word .

The man _________ book you are reading is my father.

whose

The correct word to fill in the blank is whose.

• That is used to refer to a specific thing or person. It is not the most appropriate word to use in this context, as it does not refer to the book's owner.
• Who is used to refer to a person who is performing an action. It is not the most appropriate word to use in this context, as it does not refer to the book's owner.
• Whose is used to indicate possession. It is the most appropriate word to use in this context, as it refers to the book's owner.
• Whom is the objective case of the pronoun "who." It is not the most appropriate word to use in this context, as it is not the object of the verb "are reading."