The inverse-square law correlates Illumination of the surface (E), luminous intensity (I) and the distance between the source and the surface to be illuminated (r) by the formula:

• A. \(E = \frac{{{I^2}}}{r}\)
• B. \(E = \frac{I}{r}\)
• C. \(E = \frac{I}{{{r^2}}}\)
• D. \(E = {I^2}r\)