NO.PZ2016010802000188
问题如下：
If Brazil and South Africa have free trade with each other, a common trade policy against all other countries, but no free movement of factors of production between them, then Brazil and South Africa are part of a:
选项：
A.customs union.
B.common market.
C.free trade area (FTA).
解释：
A is correct.
A customs union extends a free trade area (FTA) by not only allowing free movement of goods and services among members, but also creating common trade policy against non-members. Unlike a more integrated common market, a customs union does not allow free movement of factors of production among members.
考点：free trade area
自由贸易只要求商品的自由流动，C选项不入选。
common market仅仅还要求贸易国间的生产要素能够自由流动，所以B选项不入选。
customs union 要求所有成员国对非成员国实施同一的贸易限制措施，所以A选项入选。
题目中提到，no free movement of factors of production between them，而customs union allow free movement of goods and services among members。
