Query about Question 3 from "(GRE Big Book) Test 7 Text Completion Problems (14)" [9778]

https://www.gregmat.com/quizzes/quiz/gre-big-book-test-7-text-completion-problems-14 (Question 3)


write your question here…how is Unfortunately a support word here? and how does it help filling the blank. I chose answer supplemented.

Also how is fortunately a less obvious contrast word?