Which clause is an independent clause? A) because the earth is always rotating

B) the winter in Norway is long and harsh

C) while the horse slowly chewed on some hay

D) since summertime can be equally difficult

According to your answer the clause that is an independent clause is the answer choice B

This line implies Great Britain and the British Empire by using the term "Britannia".
The Empire is old as insinuated by the words "drooping" head.
Addressing this to Washington is showing the general that the nation of Britain, and it's empire is old...
The next lines show that it is responsible for a lot of death and destruction.