A would be the correct answer since "was" is past tense word
Only a conjunction is the correct answer
The tree is being simbolized in the Iroquois Constitution, since the Iroquois Confederation is symbolized by an Eastern white pine tree known as the Peace Tree, which is a symbol of union between the tribes.
The tree is a symbolism since the Iroquois Constitution was not agreed under a white pine, but in political meetings between its members. The tree is only a symbolic element that represents the union of these peoples.
Brian had lost a lot of his body weight since the crash, and he remains thin for years. Many of the changes Brian underwent in the wilderness seem permanent, such as his observant and thoughtful nature, and food never loses its wonder for him.
Hope this helps!