I believe the answer is C
The correct answer to this problem would be the word theirs, the first one.
The usage of their/s is kind of a tricky one since it depends on what it usually is pertaining to in the previous lines. In this problem, it would refer to our presentation. If another word, let's say presentation, is added after the blank, then the answer would be their. In this case, there isn't anything after it so the answer would be theirs.
Those that have apostrophes on them aren't an option since it isn't applicable in this situation.
Answer: I read the text and it seems perfect and I think you don't need to add anything else.
Explanation:
Analyzing the task and the way you responded it seems to me that you did it well. You were precise in each of the years. I think you should not add more since it would be a bit more extensive and the important thing about this task is to point out the most important events of each year. In my opinion, I wouldn't change anything, I think it's very good.
I could also see that you used the connectors that the statement showed. You have followed the instructions very well. Congratulations!
