Correct Answer: Tranquil

Solution : The correct option is the third option.

Explanation:
The word " tranquil " best fits the description of "quiet and peaceful" because it directly embodies a state of calmness and serenity. When something is tranquil, it's free from disturbance or agitation, creating an atmosphere of peace and quiet.
The meanings of the other options are as follows:

• Introvert refers to a person who tends to be more inward-focused, reserved, or reflective.
• Inundate means to overwhelm or flood with things or information.
• Incessant means continuing without interruption, often used to describe something that is annoyingly constant or never-ending.

Therefore, the correct answer is tranquil.