Energy Density Questions

Which two of the following five physical parameters have the same dimensions?(a) energy density(b) refractive index(c) dielectric constant(d) Young's modulus(e) magnetic field

The energy required to charge a parallel plate condenser of plate separation $d$ and plate area of cross-section $A$ such that the uniform electric field between the plates is $E$, is:

The dimension of $\frac{1}{2}{ϵ}_0{E}^2$, where ${ϵ}_0$ is permittivity of free space and $E$ is electric field, is: