To identify the substance that is not a stimulant, the characteristics and effects of each option must be analyzed:
Based on this classification, Diamorphine is the substance that is not a stimulant.
| List-I | (Postural Deformities) | List-II | (Corrective Measures) |
| A | Knock Knees | (I) | Walking on inner edge of feet |
| B | Round Shoulders | (II) | Horse Riding |
| C | Kyphosis | (III) | Wall stretch, Pull Ups |
| D | Bow Legs | (IV) | Swimming, Gym ball exercises |