B
Not A or C because they I traduces new information to the paragraph, and this cannot be conclusions. Not D because it is off topic
I uploaded the answer to a file hosting. Here's link:
tinyurl.com/wpazsebu
B Sun Yat-sen was the leader who emerged strongest following the Qing dynasty as well as the strongest Chinese leader until 1911 when he became the president.
Answer:
The second choice, hope this helps!