A common market is one where

A. all the trading nations agree commonly to levy a common and uniform tariff rate for all goods

B. all the trading nations agree commonly to rationalise tariff and non-tariff barriers mutually to promote intra-region trade

C. there is a customs union along with free intra-union movement of factors of production

D. there is an economic union along with free intra-union movement of residents

Answer: Option C