Answer:
C. phase out all trade and tariff barriers among Canada, Mexico, and the U.S
Step-by-step explanation:
The North American Free Trade Agreement (NAFTA)
This agreement creates a bloc of trade for the region, Canada, Mexico and the US.
As state on "C" It result in the elimination or reduction of barriers to trade and investment between the countries.
It will be replaced in the following year by the United States–Mexico–Canada Agreement (USMCA)
But NAFTA will keep working until this new agreement is finished.