Which two or more of the following actions would increase the energy stored in a parallel plate capacitor when a constant potential difference is applied across the plates?

1. Increasing the area of the plates

2. Decreasing the area of the plates

3. Increasing the separation between the plates

4. Decreasing the separation between the plates

5. Inserting a dielectric between the plates

(a) 2, 4 (b) 2, 3, 5 (c) 1, 4, 5 (d) 1, 3