Answer:
A.) A warm ocean current flows along the coast
Step-by-step explanation:
The sea ports which remain ice-free are called "warm-water ports." Other than those that can be found in Europe, warm-water ports can also be found in New York and Canada. This is due to the warm ocean current that flows along the coast in these areas. This allows the area to be free from ice, thus ships can just come and go. It is said that the "Gulf Stream" is responsible for bringing the warm water to Europe. However, other countries have cold-water ports just like in Russia.