The correct answer is - B. sanctions.
The most typical tool used when some countries have disagreements and protest against each other, is the sanction. The sanctions, most often, are of economic nature, with limiting the export and import of goods of a particular country, and try to weaken it economically, so that it agrees to certain things, or stops doing certain things. Not all countries have the power to put sanctions, and they are usually practiced by the bigger political players on the global scene, like the USA for example, that has put sanctions in recent years over North Korea, Iran, Syria, and even Russia.