When a number of countries agree to remove all trade barriers among themselves and at the same time charge a common tariff against non member countries, it known as
- free trade area
- common market
-
custom union
- economic community
The correct answer is: C
Explanation
A customs union is generally defined as a type of trade bloc which is composed of a free trade area with a common external tariff. Customs unions are established through trade pacts where the participant countries set up common external trade policy (in some cases they use different import quotas).