Answer:
C) The person who invited him to speak
Explanation:
As , Blake is supposed to speak at a public space , now to deliver a very informative and good speech , the best source of helop would be the person who invited him to speak .
As , The person can very well help him out with the topic and the points Blake need to keep in mind while addressing the public .
Internet and Library can help her out with the information about the subject , but the best help would be only from the peorson who asked him to speak .