What does 'doesn't infringe on copyright' mean?

It means that whatever was under copyright wasn't violated.

Explanation: The definition of a copyright is: the exclusive legal right given to the originator or an assignee to print, publish, perform, film, or record literary, artistic, or musical material, and to authorize others to do the same.  It is a protected source of material.

Your question of "doesn't infringe on copyright " means that the material stayed protected. Not violated in any way.

i would say that these are the two thesis statements best for a literary analysis essay on recurring themes in shakespeare's romeo and juliet:

1.  in romeo and juliet, shakespeare demonstrates that love comes in a variety of forms, be it romantic, familial, or between friends.

2.  shakespeare explores the struggle for identity through the character of juliet in his play romeo and juliet.

the other theses aren't reoccurring in this play. 

explanation:

i would think its c but i'm not sure