在做Base的习题时，有一个题没明白，希望有人指点一下。

题目如下：

91. The following SAS program is submitted:
proc report data = work.houses nowd;
column style price;
where price < 100000;
<insert DEFINE statements here>
title;
run;
Click the Exhibit button to view the output from the REPORT procedure.
Assume permanent variable labels have been assigned.
Which one of the following completes the program and produces the output
displayed in the exhibit?

A. define style / display width = 9;
define price / sum format = comma9. width = 10;
B. define style / width = 9;
define price / sum format = comma9. width = 10;
C. define style / group width = 9;

define price / sum format = comma9. width = 10;
D. define style / order width = 9;
define price / sum format = comma9. width = 10;

正确答案是D，可是我不明白为什么，希望大家帮助我，谢谢。

[此贴子已经被作者于2009-1-11 19:37:19编辑过]