Which of the following statements related to cost estimation methods is true? a. The most complex method of cost estimation is the high-low method. b. The scatter-graph method is used to derive an estimated line of cost behavior by graphically connecting the two cost amounts identified with the highest and lowest volume levels. c. Only high-low method has a slope and an intercept. The least squares regression method is the most accurate and reliable method to determine the cost behavior compared to scatter-graph plot and figh-low methods. None of the given answers. d. e