What Kind of Trade Barrier is This?

_____ The US congress threatens to raise taxes on Chinese imports unless China begins to address human rights abuses it is accused of committing.

The Chinese government rejects 50 tons of US corn sitting in a Chinese port because it contains corn with GMOs not approved for use in China.

_____ Japanese auto firms agree to limits set in Washington DC on the number of Japanese automobiles that may be sold in the US.

_____ Due to its increased testing of nuclear weapons, the US cuts off trade relations with North Korea.

_____ After months of wrangling and discussion, the US continues to prohibit trade with Cuba.

Shipments of Hawaiian pineapples to Peru are turned away because of pesticides not approved in Peru.

The US government applies tax credits worth $6 billion per year to firms that produce ethanol, effectively giving them money that would otherwise be paid in taxes. What is this financial assistance called?

_____ Germany raises its fees on steel imported from the US.

To prevent a price collapse, Canada reduces the amount of rice it will allow Asian nations to sell in its borders.