Voluntary export restraint is the correct answer.
The voluntary export restraint is a quota on trade that is imposed by the country that is exporting the product, usually by the request of the country that is importing these products. Through this restraint, the government establishes a limit on the quantity of a specific group of goods that can be exported to a certain country during a set period of time. Exporting countries typically agree to impose these restrictions since they fear facing punitive tariffs or possible import quotas if they refuse to do it.