A person can see clearly objects only when they lie between \(50~\text{cm}\) and \(400~\text{cm}\) from his eyes. In order to increase the maximum distance of distinct vision to infinity, the type and power of the correcting lens, the person has to use will be:
1. | \(\text{convex, +2.25 diopter}\) | 2. | \(\text{concave, -0.25 diopter}\) |
3. | \(\text{concave, -0.2 diopter}\) | 4. | \(\text{convex, +0.5 diopter}\) |