The question asks to match the heat treatment process with the correct description. Based on typical heat treatment processes: - **A. Annealing**: Softens metal, improves ductility, relieves internal stresses. - **B. Hardening (or Martensitizing)**: Increases hardness, typically through rapid cooling. - **C. Snap Temper**: Brief reheat to reduce brittleness after hardening. - **D. Cryogenic Treatment**: Improves wear resistance by cooling to cryogenic temperatures. Matching options: - **A. 1** (Complete removal of stress) - **B. 2** (Increase in hardness) - **C. 3** (Reduce brittleness) - **D. 4** (Enhance wear resistance) Given options: - 1. A, 2. B, 3. C, 4. D The correct match is **Option 1**. **Correct Option:** **A. 1, B. 2, C. 3, D. 4**