Which of the following is correct regarding cost behavior equations?

All costs are linear.

The Y$-$Intercept value in a cost behavior equation always shows the expected costs for the "low point" when using a high$-$low method.

If a data set only contains two data points, the high$-$low method and regression analysis will provide identical cost behavior equations.

The relevant range of a given cost behavior equation is unbounded.

The account analysis method is considered the most objective and easiest tool available for developing a cost behavior equation.