Two Parallel Circular Plates,each with a Radius of

Multiple Choice

Two parallel circular plates,each with a radius of
And carrying equal-magnitude surface charge densities of
Are separated by a distance of
With only air between them.How much energy is stored in these plates? (ε₀ = 8.85 × 10^-12 C²/N ∙ m²)

A) 78 nJ
B) 25 nJ
C) 7.9 nJ
D) 250 nJ