The two ends of uniform rod of thermal conductivity `K` are maintained at different but constant temperatre. The temperature gradient at any point on the rod is `d theta // dx`. The heat flow per unit time per unit cross-section of the rod is `I`.
(i) `(d theta)/(dx)` is the same for all point on the rod
(ii) `I = K (d theta)/(dx)`
A. (i) only
B. (ii) only
C. (i), (ii)
D. none
