In That car is mine, the word that works as:

Question

Accepted Answer

C. An adjective

1. It tells us something about the noun car.
2. It modifies the noun.
3. So here that is an adjective.
_Source: OpenStax Writing Guide with Handbook, Chapter 20, Editing Focus: Pronouns (CC BY 4.0)._

Answer

A verb form

Answer

A conjunction

Answer

A pronoun

In That car is mine, the word that works as:

Keep practising Unit 1B: Evidence and Argument Structure in Nonfiction