Answer:
I'm pretty sure it's -An editorial is written by the editor of a newspaper, an opinion piece is not. (sorry if it's wrong) 
Explanation:
Opinion pieces may take the form of an editorial, usually written by the senior editorial staff or publisher of the publication, in which case the opinion piece is usually unsigned and may be supposed to reflect the opinion of the periodical. 
 
        
             
        
        
        
Present
Present progressive has "-ing", present emphatic requires the verb "do" or "does" and present perfect requires "is/has/have"
        
             
        
        
        
It is choice 2: copper, bronze, and stone