The harmonious mixing of the clay ingredients, is known as A. Weathering B. Blending C. Tempering D. None of these

The correct answer is C. Tempering.

Tempering is the process of adding a small amount of a material, called a tempering agent, to clay to improve its workability and durability. The tempering agent can be a variety of materials, including sand, grog, or talc. The amount of tempering agent added will vary depending on the type of clay being used and the desired properties of the finished product.

Weathering is the process of breaking down rocks and other materials by the action of wind, water, and other natural forces. Blending is the process of mixing two or more materials together to create a new material with different properties than the original materials.

None of these options is the correct answer to the question.