The figure below shows a steel rod of 25 mm 2 cross sectional area. It is loaded at four points. K,
L, M and N. Assume ${E_{steel}}^{}$= 200 GPa. The total change in length of the rod due to loading is
(a) 1 $\mu$m (b) –10 $\mu$m
(c) 16 $\mu$m (d) –20 $\mu$m