The correct option is Plain ware.
Explanation
The pottery of the Indus Valley Civilisation is primarily wheel-made and can be broadly classified into plain ware and painted ware. While the painted ware is artistically significant, the quantitative distribution of archaeological finds reveals a clear dominance of one type.
Detailed Analysis:
- Plain Ware: This category constitutes the bulk of the pottery found at Harappan sites. It is usually made of red clay, with or without a fine red or grey slip. It includes knobs and scales for decoration but lacks elaborate painting.
- Painted Ware: Also known as Red and Black ware, this type is less common than plain ware. It involves painting black designs (geometric patterns, flora, and fauna) on a red background.
- Incised and Perforated Ware: These types are found but are relatively rare compared to the mass-produced plain pottery used for daily utility.
Key Takeaway: While the Red and Black painted pottery is the most distinctive and famous style of the Harappan civilization, Plain ware is the most abundant type found in archaeological excavations.