Answer:
(a). stand-up comedian
(b). keynote speaker
(c). ignoring information about base rates
Step-by-step explanation:
A stand up comedian is a funny and humorous person who entertains his audience by cracking jokes and making them laugh. A stand up comedian normally speaks directly in front of the live audience in a comic way.
A keynote speakers is a person who often gives speech to the audience to raise interest for a particular event, such as a large meeting or a conference. They sets an underlying theme at the conventions and conferences.
In the context, Johanna speaks to the audience in the funny way and and makes people laugh. When I met her and knew about her, I guessed that She would be a comedian than a keynote speaker.