Answer:
China´s increasing trade with other nations, and especially through maritime routes, has ensured that the Chinese seek better, and more efficient ways to help Chinese companies save money and time shipping their products around the world.
In order to ensure this process is effective, China has not only increased its economic alliegance with nations such as Greenland, but it is starting negotiations of free trade agreements also with Iceland.
Because of global warming, the famous Northwest Passage, which goes through the Arctic, has now become a possible route through which ships can pass. For China this has become a huge possibility, as it allows Chinese merchant ships to cross from the Pacific to the Atlantic in half the time than they usually take crossing the Suez Canal. And China, not being slow in taking changes of incresing its trading capacity, has capitalized on this opening route. Now, since 2013, Chinese ships go through that route, taking advantage of the receding ice caps. So, essentially, the statement: "China stands to gain the greatest benefit from a newly opened polar freshwater shipping and trade route" is absolutely true and real.