Two identical rectangular prisms each have a height of 90 centimeters cm). The base of each prism is a square, and the surface area of each prism is K cm?. If the prisms are glued together along a square base, the resulting prism has a surface area of 92 K cm?. What is the side length, in cm, of each square base?

A.) 4

B.) 8

C.) 9

D.) 16