Are there any mango trees in this garden? The underlined word is:

Explanation

The underlined word 'there' is an indefinite pronoun. It is used to refer to the existence or presence of something in a non-specific way, which is why it fits the category of indefinite pronouns. In this sentence, 'there' does not describe a noun (hence it's not an adjective), nor does it introduce a relative clause (which means it's not a relative pronoun). It also doesn't refer to individual members of a group separately, which rules out the distributive pronoun category.