The correct answer is Aegean and Black Seas
The Turkish Straits Crisis was one of the first Cold War crises, and it was a triggered event due to a disagreement between Turkey and the Soviet Union over the right of passage for ships across the Dardanelles. The roots of this crisis, however, are rooted even before the Second World War, in 1936. The Montreux Convention on the Straits Regime allowed Turkey to take full control of the Strait of the Dardanelles, as long as it allowed the passage of ships to only all other states bordering the Black Sea. However, Joseph Stalin did not agree with the resolution of the convention, and until 1939 he insisted on an alternative, in this case the simultaneous control of Turkey and the USSR of the strait. When the Ribbentrop-Molotov Pact was signed, the Soviet foreign minister, Vyacheslav Molotov, made clear the intention of the Soviets to take the Straits by force and establish a military base nearby.