Read the excerpt from Jules Verne's Journey to the Centre of the Earth.

At the time that Harry and the professor embarked upon their journey, the authenticity of the jawbone's age was questioned by several people, including the M. Elie de Beaumont with whom the professor had several angry exchanges. This discovery essentially proves the professor correct. His entire impromptu lecture could be condensed into a quick "I was right" statement!
Using the context clues, what does "impromptu" mean?

something done in anger
completed without planning
nonfiction
done with a great deal of consideration

What is darrow’s main argument and the claims he makes in this excerpt? a. darrow argues that even if the boys are horrible monsters, their deaths will not solve the problems of society; he claims that society wants the boys to be executed because people enjoy watching public executions. b. he argues that the people who should be held responsible for the crime are leopold’s and loeb’s parents since they neglected their sons; he claims that leopold and loeb were jealous of the boy they killed because he had expensive belongings they could not afford. c. darrow argues that the boys should not face the death penalty; he claims they both suffer from mental illnesses that make them unable to tell the difference between a dream and reality. d. he argues that leopold and loeb, particularly dickie loeb, should not be executed; he claims they were teenagers who didn’t have proper adult guidance, so they are not responsible for what they did.