Question

A scientist attends an annual conference hosted by the American Medical Association. At which type of event is she most likely to hear a speech given by a world-famous surgeon?
A. Keynote address
B. Panel discussion
C. Social gathering

Answer 1

A. Keynote address

In the Keynote address is most likely a world-famous surgeon would give his/her speech in order to motivate, inspire and challenge pursing scientists and medical professionals in their pursuit of their successful career and the like endeavors. 

Answer 2

If a scientist attended an annual conference hosted by the American Medical Association, it's most likely that the event where he would hear a speech from a world-famous surgeon would be during the panel discussion - b.

This is the place where people who are very known often get their chance to speak.