In the design of a shaft with significantly varying diameters over its length, you have calculated the slope of 0.01078 radian at a spur gear location when the shaft diameter is 30 mm. Does the shaft diameter need adjustment, and if so, what should be the revised shaft diameter? (a) No adjustment needed (b) Increase to reduce slope, da 64.5 mm (c) Increase to reduce slope, dar 45.5 mm (d) decrease to increase slope, darw=25.5 mm (e) decrease to increase slope, dne 20.5 mm