Which word has the similar meaning to "irritant" in Paragraph 3

A．Russia will soon suffer from isolation.
B．Russia will soon lose its satellites.
C．Former Soviet satellites resist Russia's entering WTO.
D．Some EU officials understand Russia's position.

A．EU has not signed partnership agreement with Russia.
B．EU is disappointed with at Russia's trade strategy.
C．EU wants Russia to cut down on tariffs on its meat imports.
D．EU may connect the trade conflict with Russia's entry into WTO.