Which of the following statements about the segment margin is not true?

multiple choice

In preparing a segmented income statement, the variable expenses are deducted from sales to yield the contribution margin for each segment.

The segment margin is obtained by deducting the common fixed costs that have been allocated to a segment from that segment's contribution margin.

The segment margin represents the margin available after a segment has covered all of its own costs.

The segment margin is the best gauge of the long$-$run profitability of a segment because it includes only those costs that are caused by the segment.