Answer:
The Arctic consists of desert and tundra vegetations. The desert vegetation consists of algae, lichens, and mosses. Lichens are the most dominant plants.
I think maybe there were some options that you didn't copy?
Else I can say that a letter written at the time of a historical event would be a primary source - as opposed to a secondary source which is written well after the relevant event.
Personally, I would say Vietnam. This is because the war in Vietnam started in 1955, escalated even more when the U.S. came in the 60s, and finally came to a close in 1975. Vietnam has fought for independence for 20 years, and that's my reason why.
