Final answer:
In the sentence, "Mr. Jones" is identified as a proper noun because it names a specific teacher, which is a unique identifier and is capitalized.
Step-by-step explanation:
In the sentence provided, "Mr. Jones" serves as a proper noun. Proper nouns are unique names given to specific people, places, things, or titles and they are always capitalized. In this instance, "Mr. Jones" refers to a specific person, making it a proper noun rather than a common, possessive, or collective noun. It is neither a class of person (common noun) nor does it show ownership (possessive noun) nor does it represent a group (collective noun).