Sufres is the answer. The reason for this is because it establishes the present tense through a request. So its: no sufres por mi.
Hello!
"El árbol es ______", translates to "This tree is ______." Since we are given two choice, suyo and suya, one of the them is obviously feminine and ther other is masculine.
Since "el árbol" is masculine, we use the possessive word, "suyo", meaning "yours".
Therefore, el árbol es suyo.
What are you going to bring to the party?
Or
What did you bring to the party?