Answer: Flat
Step-by-step explanation:
The character who said this is a servant of the house of Capulet named Sampson. He is a flat character because flat characters are simply placeholders in a story that have no depth attached to them. They also do not grow in the story but rather remain as they are from the beginning of the story to the end.
Sampson's sole purpose in Act 1 is to depict the hatred between the servants of the Houses of Capulet and Montague and throughout the Act is shown to be full of hatred for the Montagues. His view never changed and his role wasn't of consequence. He is a flat character.