Which of the following is least likely to

问题单项选择题

Which of the following is least likely to describe a cross-sectional data set（）

A. An index's quarterly returns in 2011.

B. The annual sales growth of companies in mining industry in 2011.

C. Price-to-earnings ratios of publicly traded companies at the end of 2011.

答案

参考答案：A

解析：

选项A中的2011年每季度的回报是时间序列数据(time-series dada)。而另外两个选项，即2011年采掘行业的年销售增长率和2011年末的市盈率是截面序列数据(crosssectional data)。