问题如下：
Which of following is least correct about common-size analysis of the income statement?
选项：
A. Common-size analysis could make different companies or the same company across time period comparable, because it removes the effect of size.
B. Each item of income statement is as a percentage of earnings under common-size analysis
C. The analyst could compare strategies among different companies according to common-size statement.
解释：
B is correct. Common size income statement= each item/revenue, is as a percentage of revenue, not earnings.
a是错在后半句吗？如果不是，能不能指出a的错误点
