When you are determining the project activities to be shortened with the smallest increase in cost per unit of time, you need to have some assumptions. Which of the following CAN NOT be one of the assumptions? Crash time represents a limit-the greatest time reduction possible under realistic conditions. The cost-time relationship is non-linear and dynamically determined. Normal time assumes low-cost, efficient methods to tomplete the activity. All accelerations must occur within the normal and crash times. Slope represents a constant cost per unit of time