Match the items in Column I with the relevant items in Column II.
| Column I | Column II |
| A. Hydrogen peroxide is used as a | 1. Sodium hexametaphosphate |
| B. Used in Calgon method | 2. Clark's method |
| C. Temporary hardness of hard water is removed by | 3. Reducing agent |
Codes
| A | B | C | |
| 1. | 3 | 2 | 1 |
| 2. | 1 | 2 | 3 |
| 3. | 3 | 1 | 2 |
| 4. | 2 | 1 | 3 |
