Answer:
Proper Noun
Step-by-step explanation:
"Dennis" is a name of a person. A proper noun is used for an individual person, place, or organization, spelled with initial capital letters like "Wal-Mart" or "Starbucks" or they can even be names like "Clarissa" or "Debbie".
Therefore, making "Dennis" a proper noun because it is the name of a person. :)