求教：SAS ADV考试机经Lab中有关SQL合并的题是哪种合并

题目：        use SQL to create a new table that contains all unique values of Make and Type from cert.cars, and Rebate from cert.rebate. For Rebate, show Make and Type if matching; if no matching Make and Type, show missing. Only three variable: Make, Type, Rebate.

个人理解这个是用right join。有大侠可以指点一二吗？以下CODE对吗

Proc sql;
Create table cert.car as
Select cars.make, cars.type, rebate.rebate
From cert.cars right join cert.rebate
On cars.make=rebate.make and cars.type=rebate.type
Quit;

我考试用的left join,我看我SQL部分满分，应该是对的。

考试left join +1