It is an opinion rather than a fact because there is no data to support that all service members and veterans have challenges when they return. There are no factual statistics or data to back up this claim so therefore it is an opinion
D,<span> Sara suddenly became very ill; therefore, she went to see her doctor.</span>
C. She was lonely, and the other men were playing horseshoes
(Enjoy reading Of Mice and Men!)
Hope this helps!
(It didn’t let me add the text so I had to write it in my notes)