Step 1: Identifying materials for strong clay in terracotta.
To enhance the strength and workability of clay for terracotta, materials such as grog, cotton, and stone are incorporated. Metal is not a standard component in clay preparation.
Step 2: Analyzing the options.
- (1) (B) and (D) only: Incorrect, as metal is excluded from the materials used in strong clay.
- (2) (A), (B) and (D) only: Incorrect, as metal is not employed in the production of strong clay.
- (3) (A), (C) and (D) only: Correct. Grog, cotton, and stone are the primary materials utilized to improve clay strength.
- (4) (A) and (C) only: Incorrect, as stone is also vital for strengthening the clay.
Step 3: Conclusion.
Therefore, the correct selection is (A), (C), and (D) only, corresponding to option (3).