Step 1: Understanding the Concept:
This question asks to identify the specific part of the Mridangam responsible for producing low-frequency, or bass, sounds.
Step 2: Detailed Explanation:
The Mridangam is a two-sided drum. The two heads are distinct in size and sound:
- The right side ('Valanthalai') is smaller and produces high-pitched, metallic sounds.
- The left side ('Toppi') is larger. A paste of flour and water is applied to it before playing to lower its pitch and give it a characteristic deep, resonant bass sound.
The other options ('Chapu', 'Meetu', 'Arachapu') are names of strokes played on the instrument, not parts of the instrument itself.
Step 3: Final Answer:
The Toppi, or the left side of the Mridangam, produces the bass sound.