A company makes computer chips from square wafers of silicon. A process engineer wants to keep the side length of a wafer very close to 18 mm and needs to know how the area A(x) of a wafer changes when the side length x changes. Find A'(18) (in mm²/mm).A'(18) =_________________ mm²/mmExplain the meaning of A'(18) in the context of this problem.(A)A'(18) represents the rate at which the area is increasing with respect to the s ide length as x reaches 18 mm.(B)A'(18) represents the rate at which the side length is increasing with respect to the area as x reaches 18 mm.(C)A'(18) represents the area as the side length reaches 18 mm.(D)A'(18) represents the rate at which the area is increasing as x reaches 36 mm.(E) A'(18) represents the rate at which the area is increasing with respect to the side length as A reaches 36 mm².