The intensity of light at a distance x meters from a source is modeled by the function R given by R(x) = k/x², where k is a positive constant. Which of the following gives the average intensity of the light between 4 meters and 6 meters from the source?
(A) 25k
(B) −Kk/6 + k/4
(C)1/2(−Kk/6 +k/4)
(D) 1/2(k/16 + k/36)
